Statistical Inference

Problem 401

```latex A newspaper published an article about a study in which researchers subjected laboratory gloves to stress. Among 256 vinyl gloves, $66\%$ leaked viruses. Among 256 latex gloves, $13\%$ leaked viruses. Using the accompanying display of the technology results, and using a 0.01 significance level, test the claim that vinyl gloves have a greater virus leak rate than latex gloves. Let vinyl gloves be population 1.
(i) Click the icon to view the technology results.
What are the null and alternative hypotheses?
A. $H_{0}: p_{1} \neq p_{2}$ \quad $H_{1}: p_{1} = p_{2}$
B. $H_{0}: p_{1} > p_{2}$ \quad $H_{1}: p_{1} = p_{2}$
C. $H_{0}: p_{1} = p_{2}$ \quad $H_{1}: p_{1} = p_{2}$
D. $H_{0}: p_{1} < p_{2}$ \quad $H_{1}: p_{1} = p_{2}$
E. $H_{0}: p_{1} = p_{2}$ \quad $H_{1}: p_{1} > p_{2}$
F. $H_{0}: p_{1} = p_{2}$ \quad $H_{1}: p_{1} \neq p_{2}$
Identify the test statistic. $\square$ (Round to two decimal places as needed.)
The user took a picture with their phone and the text was extracted above. The user then had a dialogue with an AI Assistant to help clarify the instructions.
Dialogue Transcript:
Hi there! It looks like we have a hypothesis testing problem regarding virus leak rates for vinyl and latex gloves. However, there seems to be some missing information, such as the technology results mentioned. Could you please provide any missing details or clarify what you'd like help with?
Once I have all the details, I'll be happy to help you with the steps for this hypothesis testing problem. What is the rest statistic and the p-value ```

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Problem 402

A true/false test has 90 questions. Suppose a passing grade is 54 or more correct answers. Test the claim that a student knows more than half of the answers and is not just guessing. Assume the student gets 54 answers correct out of 90 . Use a significance level of 0.05 . Steps 1 and 2 of a hypothesis test procedure are given below. Show step 3 , finding the test statistic and the p-value and step 4 , interpreting the results.
Step 1: $H_{0}: p=0.50$ $H_{a}: p>0.50$
Step 2: Choose the one-proportion z-test. Sample size is large enough, because $n p_{0}$ is $90(0.5)=45$ and $n\left(1-p_{0}\right)=$ $90(.5)=45$ , and both are more than 10 . Assume the sample is random. Step 3: Compute the $z$ -test statistic, and the $p$ -value. $z=$ $\square$ (Round to two decimal places as needed.) $p$ -value $=$ $\square$ (Round to three decimal places as needed.)

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Problem 403

In Country A, the population mean height for 10-year-old girls is 53.6 inches with a standard deviation of 2.1 inches. Suppose a random sample of 15 10-year-old girls from Country B is taken and that these girls had a sample mean height of 52.6 inches with a standard deviation of 2.4 inches. Assume that heights are Normally distributed. Complete parts (a) through (c) below.
Since the p-value is $\square$ greater than the significance level, do not reject $\mathrm{H}_{0}$ . There is insufficient evidence conclude that the height for 10-year-old girls from Country $B$ is significantly different from the Country $A$ population at a significance level of 0.05 . b. Now suppose the sample consists of 35 girls instead of 15 . Repeat the test.
Determine the null and alternative hypotheses. Choose the correct choice below. A. $H_{0}: \mu=53.6$ B. $H_{0}: \mu<53.6$ C. $\mathrm{H}_{0}: \mu=53.6$ $H_{a}: \mu \neq 53.6$ $H_{a}: \mu=53.6$ $H_{a}: \mu>53.6$ D. $\begin{array}{l} \mathrm{H}_{0}: \mu \neq 53.6 \\ \mathrm{H}_{\mathrm{a}}: \mu=53.6 \end{array}$ E. $H_{0}: \mu=53.6$ F. $\mathrm{H}_{0}: \mu>53.6$ $H_{a}: \mu<53.6$ $H_{a}: \mu=53.6$
Find the test statistic. $\mathrm{t}=-2.46$ (Round to two decimal places as needed.) Find the $p$ -value. $p=\square$ (Round to three decimal places as needed.) $\square$

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Problem 404

In a large clinical trial, 398,546 children were randomly assigned to two groups. The treatment group consisted of 197,285 children given a vaccine for a certain disease, and 28 of those children developed the disease. The other 201,261 children were given a placebo, and 98 of those children developed the disease. Consider the vaccine treatment group to be the first sample. Identify the values of $n_{1}, \hat{p}_{1}, \hat{q}_{1}, n_{2}, \hat{p}_{2}, \hat{q}_{2}, \bar{p}$ , and $\bar{q}$ . $n_{1}=\square$

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Problem 405

test the claim.
Claim: $\square$ $\mathrm{p} \leq 0.5$ which corresponds to $\square$ HO: $p \leq 0.5$
Opposite: Select an answer which corresponds to \begin{tabular}{|l|} \hline Select an answer \\ \hline Select an answer \\ H1: $p \neq 0.5$ \\ H1: $p<0.5$ \\ H0: $p=0.5$ \\ HO: $p \neq 0.5$ \\ HO: $p \leq 0.5$ \\ HO: $u \geq 0.5$ \\ H1: $p>0.5$ \\ \hline \end{tabular}
The $p$ -value is: $\square$ 0.0012 $\square$ 3.05 (to 2 decimals) The test statistic is: The test is: (to 4 decimals)
Based on this we: Reject the null hypothesis
Conclusion There $\square$ appear to be enough evidence to support the claim that the proportion of patients taking Lipitor who experience flu-like symptoms is larger than $50 \%$ .

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Problem 406

A research company published survey results from two random samples. Both samples were asked "Have you listened to an audio book in the last year?" Use the accompanying results from the study to complete parts (a) and (b). \begin{tabular}{lccc} Listened to an & & & \\ audio book & 2015 & 2018 & Total \\ Yes & 232 & 366 & 598 \\ No & 1684 & 1652 & 3336 \\ Total & 1916 & 2018 & \end{tabular}
The sample proportion for 2015 is $\square$ less than the sample proportion for 2018. b. Are a greater proportion listening to audio books in 2018 compared to 2015? Test the hypothesis that a great proportion of people listened to an audio book in 2018 than in 2015. Use a 0.01 significance level.
Consider the first sample to be the 2015 group and the second sample to be the 2018 group. What are the null and alternative hypotheses for the hypothesis test? A. $H_{0}: p_{1}=p_{2}$ B. $H_{0}: p_{1}>p_{2}$ C. $H_{0}: p_{1}=p_{2}$ $H_{a}: p_{1}<p_{2}$ $H_{a}: p_{1}=p_{2}$ $H_{a}: p_{1} \neq p_{2}$ D. $H_{0}: p_{1}=p_{2}$ E. $H_{0}: p_{1}<p_{2}$ F. $H_{0}: p_{1} \neq p_{2}$ $H_{a}: p_{1}>p_{2}$ $H_{a}: p_{1}=p_{2}$ $H_{a}: p_{1}=p_{2}$
Identify the test statistic. $z=$ $\square$ (Round to two decimal flaces as needed.)

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Problem 407

Question 5 5 pts 1 Details
A sample of 106 men was taken and it was found that 32 owned cats. A sample of 157 women was taken and it was found that 82 owned cats. Test the claim that the proportion of men who own cats is smaller than than the proportion of women who own cats at the .05 significance level.
Claim: $\square$ p $1 \geq p 2$ which corresponds to $\square$ Select an answer $\downarrow$
Opposite: $\square$ Select an answer $\sqrt{2}$ which corresponds to $\square$
The test is: Select an answer $\$$ \square$
The test statistic is: $z=$ $\square$ (to 2 decimals)
The p -value is: $\square$ (to 4 decimals)
Based on this we: $\square$ Select an answer
Conclusion There $\square$ does appear to be enough evidence to support the claim that the proportion of men who own cats is smaller than than the proportion of women who own cats.

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Problem 408

The below data shows the amount of time (in seconds) that animated Disney movies showed the use of tobacco and alcohol. Test the claim that the mean difference in time of tobacco use vs. alcohol use is equal to zero at the 0.01 significance level.
You may want to use a spreadsheet to help you solve this problem \begin{tabular}{|r|r|} \hline Tobacco & Alcohol \\ \hline 61.7 & 82 \\ \hline 59.8 & 84.5 \\ \hline 57.5 & 93.2 \\ \hline 60.1 & 79.5 \\ \hline 61.7 & 85.6 \\ \hline 62.9 & 110.6 \\ \hline 60.1 & 141.6 \\ \hline 64.9 & 104.4 \\ \hline 44.2 & 120.3 \\ \hline 41.9 & 85.4 \\ \hline 59.4 & 99.9 \\ \hline 52.6 & 89.3 \\ \hline 77.6 & 166.1 \\ \hline 48.6 & 57.5 \\ \hline 56.2 & 104.2 \\ \hline 61.7 & 72.6 \\ \hline 66.1 & 67.6 \\ \hline 63.4 & 64.9 \\ \hline 49.5 & 51 \\ \hline 51.2 & 80.5 \\ \hline \end{tabular}
Claim: Select an answer which corresponds to Select an answer Opposite: Select an answer $\vee$ which corresponds to Select an answer
The test is: Select an answer
The test statistic is: $\square$ (to 3 decimals)
The Critical Value is: $\square$ (to 3 decimals)

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Problem 409

1. As part of a quality control process for computer chips, an engineer at a factory randomly samples 212 chips during a week of production to test the current rate of chips with severe defects. She finds that 27 of the chips are defective. a) What population is under consideration in the data set? b) What parameter is being estimated? c) What is the point estimate for the parameter? d) What is the name of the statistic we use to measure the uncertainty of the point estimate? e) Compute the value from part (d) for this context. f) The historical rate of defects is $10 \%$ . Should the engineer be surprised by the observed rate of defects during the current week?

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Problem 410

ufgabe 2: Gummibärchen Ein Hersteller behauptet, dass $20 \%$ der Gummibärchen seiner Produktion rot sind. (a) Stellen Sie eine Hypothese und eine (rechnerisch belegte!) Entscheidungsregel für den Fall auf, dass man eine Stichprobe mit 60 Gummibärchen zufällig entnimmt. (Irrtumswahrscheinlichkeit max. $5 \%$ ) (b) Der Produltionsleiter zweifelt Ihren Test an und behauptet, $\mu \pm 8$ rote Gummibärchen seien kein Grund zur Sorge. Berechnen Sie seine Irrtumswahrscheinlichkeit! (c) Der Geschâtsfiuhrer will es ganz genau wissen und zählt nach: In seiner Stichprobe findet er 45 griune, 51 weiße, 30 rote, 34 gelbe und 40 orange Gummibärchen. Beurteilen Sie die Mischung - allerdings nur(!) im Bezug auf den Anteil der roten Gummibärchen!

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Problem 411

Price of eggs and milk: The following table presents the average price in dollars for a dozen eggs and a gallon of milk for each month from January through October 2003. Use a TI-84 calculator to answer the following. \begin{tabular}{cc} \hline Dozen Eggs & Gallon of Milk \\ \hline 0.94 & 2.85 \\ 0.89 & 2.76 \\ 1.03 & 2.85 \\ 0.88 & 2.89 \\ 0.92 & 2.91 \\ 0.86 & 2.93 \\ 0.93 & 2.89 \\ 0.92 & 2.94 \\ 0.92 & 2.95 \\ 0.94 & 2.89 \end{tabular} Send data to Excel
Part 1 of 3 Compute the least-squares regression line for predicting the price of milk from the price of eggs. Round the slope and $y$ -intercept to at least four decimal places. Regression line equation: $\hat{y}=0.8128 x+2.099{ }^{\star}$
Correct Answer: $\widehat{y}=3.0598-0.1883 x$
Part 2 of 3
If the price of eggs differs by $\$ 0.35$ from one month to the next, by how much would you expect the price of milk to differ? Round your answer to two decimal places. The price of milk would differ by $\$-0.07$ . $\square$
Part: $2 / 3$
Part 3 of 3
Predict the price of milk in a month when the price of eggs is $\$ 1.94$ . Round the answer to two decimal places. The price of milk is predicted to be $\$$ $\square$

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Problem 412

Government funding: The following table presents the budget (in millions of dollars) for selected organizations that received U.S. government funding for arts and culture in both 2006 and last year. \begin{tabular}{llc} \hline Organization & $\mathbf{2 0 0 6}$ & Last Year \\ \hline Organization 1 & 460 & 450 \\ Organization 2 & 247 & 229 \\ Organization 3 & 142 & 154 \\ Organization 4 & 124 & 165 \\ Organization 5 & 95 & 156 \\ Organization 6 & 18 & 42 \\ Organization 7 & 2 & 3 \\ \hline \end{tabular}
Part: $0 / 3$
Part 1 of 3
Compute the least-squares regression line for predicting last year's budget from the 2006 budget. Round the slope and $y$ -intercept to four decimal places as needed.
The equation for the least-squares regression line is $\widehat{y}=\square$ . $\square$

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Problem 413

4. Use the following ANCOVA output to interpret the results in relation to the research scenario. Use the pairwise comparison table if appropriate.
Tests of Between-Subjects Effects \begin{tabular}{|c|c|c|c|c|c|c|} \hline \multicolumn{7}{|l|}{Dependent Variable: SAT} \\ \hline Source & Type III Sum of Squares & df & Mean Square & F & Sig. & \begin{tabular}{l} Partial Eta \\ Squared \end{tabular} \\ \hline Corrected Model & $816828.028^{\text {a }}$ & 4 & 204207.007 & 13.884 & <. 001 & . 326 \\ \hline Intercept & 3075912.553 & 1 & 3075912.553 & 209.138 & $<.001$ & . 645 \\ \hline gpa & 420184.694 & 1 & 420184.694 & 28.569 & <. 001 & . 199 \\ \hline program & 329653.302 & 3 & 109884.434 & 7.471 & <. 001 & . 163 \\ \hline Error & 1691368.639 & 115 & 14707.553 & & & \\ \hline Total & 164491000.00 & 120 & & & & \\ \hline Corrected Total & 2508196.667 & 119 & & & & \\ \hline \end{tabular} a. R Squared $=.326$ (Adjusted R Squared $=.302$ )
Estimates \begin{tabular}{|c|c|c|c|c|} \hline \multicolumn{5}{|l|}{Dependent Variable: SAT} \\ \hline \multirow[b]{2}{}{SAT prep program} & \multirow[b]{2}{}{Mean} & \multirow[b]{2}{}{Std. Error} & \multicolumn{2}{|l|}{95\% Confidence Interval} \\ \hline & & & Lower Bound & Upper Bound \\ \hline none & $1121.194^{\text {a }}$ & 22.224 & 1077.174 & 1165.215 \\ \hline Kaplan & $1117.862^{\text {a }}$ & 22.156 & 1073.976 & 1161.748 \\ \hline College Board & $1160.041^{\text {a }}$ & 22.220 & 1116.028 & 1204.054 \\ \hline Khan Academy & $1248.236^{\text {a }}$ & 22.157 & 1204.347 & 1292.125 \\ \hline \end{tabular} a. Covariates appearing in the model are evaluated at the following values: GPA $=2.6307$ .
Pairwise Comparisons Dependent Variable: SAT \begin{tabular}{|c|c|c|c|c|c|c|} \hline \multirow[b]{2}{}{(l) SAT prep program} & \multirow[b]{2}{}{(J) SAT prep program} & \multirow[b]{2}{}{\begin{tabular}{l} Mean \\ Difference (I-J) \end{tabular}} & \multirow[b]{2}{}{Std. Error} & \multirow[b]{2}{}{Sig. ${ }^{\text {b }}$ } & \multicolumn{2}{|l|}{95\% Confidence Interval for Difference ${ }^{\text {b }}$ } \\ \hline & & & & & Lower Bound & Upper Bound \\ \hline \multirow[t]{3}{}{none} & Kaplan & 3.332 & 31.333 & 1.000 & -80.786 & 87.451 \\ \hline & College Board & -38.846 & 31.539 & 1.000 & -123.519 & 45.826 \\ \hline & Khan Academy & -127.042 & 31.432 & <. 001 & -211.427 & -42.656 \\ \hline \multirow[t]{3}{}{Kaplan} & none & -3.332 & 31.333 & 1.000 & -87.451 & 80.786 \\ \hline & College Board & -42.179 & 31.425 & 1.000 & -126.544 & 42.186 \\ \hline & Khan Academy & -130.374 ${ }^{\text { }}$ & 31.355 & <. 001 & -214.550 & -46.198 \\ \hline \multirow[t]{3}{}{College Board} & none & 38.846 & 31.539 & 1.000 & -45.826 & 123.519 \\ \hline & Kaplan & 42.179 & 31.425 & 1.000 & -42.186 & 126.544 \\ \hline & Khan Academy & -88.195 & 31.330 & . 034 & -172.306 & -4.084 \\ \hline \multirow[t]{3}{}{Khan Academy} & none & $127.042^{}$ & 31.432 & <. 001 & 42.656 & 211.427 \\ \hline & Kaplan & $130.374^{}$ & 31.355 & <. 001 & 46.198 & 214.550 \\ \hline & College Board & $88.195^{}$ & 31.330 & . 034 & 4.084 & 172.306 \\ \hline \end{tabular}
Based on estimated marginal means *. The mean difference is significant at the .05 level. b. Adjustment for multiple comparisons: Bonferroni.
5. Based on your interpretation of the results, what would you tell students preparing to take the SAT?

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Problem 414

Compute the correlation coefficient. \begin{tabular}{c|ccccccc} $x$ & 27 & 24 & -7 & 39 & 11 & 15 & -9 \\ \hline $y$ & 11 & -7 & 12 & -9 & 21 & 8 & -4 \end{tabular}
The correlation coefficient is $r=$ $\square$ Round the answer to three decimal places as needed.

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Problem 415

Select the appropriate word or phrase to complete each sentence.
Part: 0 / 2 $\square$
Part 1 of 2
If the correlation coefficient is equal to 0 , the slope of the least-squares regression line will be equal to $\square$ (Choose one) .

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Problem 416

Blood pressure: A blood pressure measurement consists of two numbers: the systolic pressure, which is the maximum pressure taken when the heart is contracting, and the diastolic pressure, which is the minimum pressure taken at the beginning of the heartbeat. Blood pressures were measured, in millimeters of mercury ( mmHg ), for a sample of 10 adults. The following table presents the results. Use a T1-84 calculator to answer the following. \begin{tabular}{cccc} \hline Systolic & Diastolic & Systolic & Diastolic \\ \hline 112 & 75 & 157 & 103 \\ 107 & 71 & 154 & 94 \\ 110 & 74 & 134 & 87 \\ 108 & 69 & 115 & 83 \\ 105 & 66 & 113 & 77 \\ \hline \end{tabular}
Based on results published in the Journal of Human Hypertension Send data to Excel
Part: $0 / 4$
Part 1 of 4
Compute the least-squares regression line for predicting the diastolic pressure from the systolic pressure. Round the slope and $y$ -intercept to at least four decimal places.
Regression line equation: $\hat{y}=$ $\square$

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Problem 417

Blood pressure: A blood pressure measurement consists of two numbers: the systolic pressure, which is the maximup pressure taken when the heart is contracting, and the diastolic pressure, which is the minimum pressure taken at the llo beginning of the heartbeat. Blood pressures were measured, in millimeters of mercury ( mmHg ), for a sample of 10 adults. The following table presents the results. Use a TI-84 calculator to answer the following. \begin{tabular}{cccc} \hline Systolic & Diastolic & Systolic & Diastolic \\ \hline 112 & 75 & 157 & 103 \\ 107 & 71 & 154 & 94 \\ 110 & 74 & 134 & 87 \\ 108 & 69 & 115 & 83 \\ 105 & 66 & 113 & 77 \\ \hline \end{tabular}
Based on results published in the Journal of Human Hypertension Send data to Excel
Part: $0 / 4$
Part 1 of 4
Compute the least-squares regression line for predicting the diastolic pressure from the systolic pressure. Round the slope and $y$ -intercept to at least four decimal places.
Regression line equation: $\hat{y}=0.7157 x-6.8931$
Part: $1 / 4$
Part 2 of 4
Is it possible to interpret the $y$ -intercept? Explain. (Choose one) $\nabla$ , the $x$ -values are all (Choose one) $\nabla$ .

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Problem 418

Blood pressure: A blood pressure measurement consists of two numbers: the systolic pressure, which is the maximum pressure taken when the heart is contracting, and the diastolic pressure, which is the minimum pressure taken at the beginning of the heartbeat. Blood pressures were measured, in millimeters of mercury ( mmHg ), for a sample of 10 adults. The following table presents the results. Use a T1-84 calculator to answer the following. \begin{tabular}{cccc} \hline Systolic & Diastolic & Systolic & Diastolic \\ \hline 112 & 75 & 157 & 103 \\ 107 & 71 & 154 & 94 \\ 110 & 74 & 134 & 87 \\ 108 & 69 & 115 & 83 \\ 105 & 66 & 113 & 77 \\ \hline \end{tabular}
Based on results published in the Journal of Human Hypertension Send data to Excel
Part: $0 / 4$
Part 1 of 4
Compute the least-squares regression line for predicting the diastolic pressure from the systolic pressure. Round the slope and $y$ -intercept to at least four decimal places.
Regression line equation: $\hat{y}=0.7157 x-6.8931$
Part: $1 / 4$
Part 2 of 4
Is it possible to interpret the $y$ -intercept? Explain. $\square$ No , the $x$ -values are all $\square$ negative . $\square$ $\square$

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Problem 419

\begin{problem} Statistically, $20\%$ of children in California are diagnosed with asthma. A pediatrician believes this proportion is now significantly higher than it used to be. A recently published study reports that, of 357 randomly selected children in California, 80 have a diagnosis of asthma. Does the study support the pediatrician's belief that more than $20\%$ of children in California are now diagnosed with asthma? Use $\alpha=0.01$ . Answer questions $1-8$ .
\begin{enumerate} \item The population of interest is: All children in California with asthma. \item The sample used is: 80 children diagnosed with asthma. \item The variable of interest is: 357 randomly selected children. \item This variable is (circle one): \textbf{Numerical} \quad \textbf{Categorical} \item STEP I: State the null and alternative hypotheses using proper notation. \begin{array}{l} H_{0}= \\ H_{a}= \end{array} \] \item STEP 2: Report the significance level and check the conditions for a valid test. \item STEP 3: Compute the test statistic and p$-value (report the calculator option and inputs). \item STEP 4: Make the decision and write the conclusion (use the class template). \end{enumerate} \end{problem}

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Problem 420

Price of eggs and milk: The following table presents the average price in dollars for a dozen eggs and a gallon of milk for each month from February through November 2004. \begin{tabular}{cc} \hline Dozen Eggs & Gallon of Milk \\ \hline 1.01 & 2.81 \\ 1.13 & 2.85 \\ 1.50 & 2.91 \\ 1.03 & 3.14 \\ 1.00 & 2.99 \\ 1.63 & 3.09 \\ 1.24 & 3.30 \\ 1.05 & 2.89 \\ 0.92 & 3.06 \\ 1.04 & 3.22 \\ \hline \end{tabular} Send data to Excel
Part: $0 / 3$
Part 1 of 3
Compute the least-squares regression line for predicting the price of milk from the price of eggs. Round the slope and $y$ -intercept to at least four decimal places.
Regression line equation: $\hat{y}=$ $\square$

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Problem 421

Compute the least-squares regression line for predicting $y$ from $x$ given the following summary statistics. Round the slope and $y$ -intercept to at least four decimal places. $\begin{array}{lll} \bar{x}=6 & s_{x}=2 & \bar{y}=103 \\ s_{y}=101 & r=-0.86 \end{array}$
Send data to Excel
Regression line equation: $\hat{y}=$ $\square$

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Problem 422

How smart is your phone? A random sample of 8 Samsung Galaxy smartphones being sold over the internet in 2013 had the following prices, in dollars: \begin{tabular}{llllll} \hline 149 & 135 & 249 & 349 & 299 & 249 \\ 199 & 169 & & & & \\ \hline \end{tabular} Send data to Excel
Assume the population standard deviation is $\sigma=85$ . Perform the following.
Part: $0 / 3$
Part 1 of 3 (a) Explain why it is necessary to check whether the population is approximately normal before constructing a confidence interval.
It is necessary to check whether the population is approximately normal because (Choose one) Skip Part Check Save For Later Submit Ass - 2024 McGraw Hill LLC. All Rights Reserved. Terms of Use I Privacy Center

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Problem 423

Module 13 Qulz Sec. 9.-9.2 Question 1 of 6 (1 point) I Question Attempt: 1 of 1
Managers at an automobile manufacturing plant would like to examine the mean completion time, $\mu$ , of an assembly line operation. The past data indicate that the mean completion time is 41 minutes, but the managers have good reason to believe that this value has increased. The managers plan to perform a statistical test.
After choosing a random sample of assembly line completion times, the managers compute the sample mean completion time to be 44 minutes. The standard deviation of the population of completion times can be assumed not to have changed from the previously reported value of 3 minutes.
Based on this information, complete the parts below. (a) What are the null hypothesis $H_{0}$ and the alternative hypothesis $H_{1}$ that should be used for the test? $\begin{array}{l} H_{0}: \square \\ H_{1}: \square \end{array}$

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Problem 424

Compute r, the correlation coefficient, using the following data. \begin{tabular}{|c|c|c|c|c|c|c|} \hline $\mathbf{x}$ & 8 & 2 & 6 & 7 & 5 & 1 \\ \hline $\mathbf{y}$ & 1 & 7 & 3 & 2 & 5 & 9 \\ \hline \end{tabular} $r=\square$ (Round to two decimal places.)

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Problem 425

The accompanying data represent the percentages of teenagers in various countries that have used certain drugs. Complete parts (a) through (c) below. \begin{tabular}{|l|c|c|c|c|c|c|c|c|c|c|c|} \hline Country & A & B & C & D & E & F & G & H & I & J & K \\ \hline Drug 1, $\boldsymbol{x}$ & 22 & 18 & 40 & 4 & 38 & 18 & 22 & 5 & 8 & 53 & 33 \\ \hline Other Drugs, $\boldsymbol{y}$ & 4 & 4 & 22 & 0 & 15 & 7 & 14 & 3 & 4 & 30 & 25 \\ \hline \end{tabular} a. Determine the correlation coefficient between the percentage of teenagers who have used Drug 1 and the percentage who have used other drugs. $\mathrm{r}=\square$ (Round to two derimal places as needed.)

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Problem 426

2. A simple random sample of 35 colleges and universities in the U.S. had a mean tuition of $\$ 18,702$ with e standard derriation of $\$ 10,653$ . Construct $\$ 95 \%$ - Onfidence interval for the mean tuition for af colleges and universities in the United states. $\begin{array}{l} \bar{x}=18702 \\ S=10653 \end{array}$

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Problem 427

3. You want to determine if there are differences in the caloric content of the different types of hot dogs (beef vs. mixed meat vs. vegetarian). d) What alpha level would you use with your previously selected statistical test? 0.05 0.017 0.5 0.17

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Problem 428

Question 11 1 pts
2. You want to determine if there is a difference in the "pre blood pressure" measurements for the individuals who were randomly assigned to the calcium and placebo groups. This "pre blood pressure" measurement is the blood pressure measurement taken prior to receiving any treatment. b) What is the alternative hypothesis? Pre blood pressure measurements will be significantly lower in the calcium compared to placebo group Pre blood pressure measurements will not be affected in the calcium group compared to placebo group

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Problem 429

2. You want to determine if there is a difference in the "pre blood pressure" measurements for the individuals who were randomly assigned to the calcium and placebo groups. This "pre blood pressure" measurement is the blood pressure measurement taken prior to receiving any treatment. a). What is the null hypothesis? There is no significant difference in pre blood pressure measurements between the calcium and placebo groups. There is a significant difference in pre blood pressure measurements between the calcium and placebo groups.

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Problem 430

Stanford University conducted a study of whether running is healthy for men and wornen over age 50 . During the first eight years of the study, $7 \%$ of the 692 members of the 50 -Plus Fitness Association died. We are interested in the proportion of people over 50 who ran and died in the same eight-year period. a. Define the random variables $X$ and $P^{\prime}$ in words. $X$ is the number of households in the survey where women make the majority of the purchasing decisions. $\boldsymbol{P}^{\prime}$ is the population proportion of households where women make the majority of the purchasing decisions. $\boldsymbol{X}$ is the number of people over 50 who ran and died in the same eight-year period. $\boldsymbol{P}^{\prime}$ is the population proportion of people over 50 who ran and died in the same eight-year period from the sample of 692 members of the 50-Plus Fitness Association. $X$ is the number of people over 50 who ran and died in the same eight-year period. $P^{\prime}$ is the estimate of proportion of people over 50 who ran and died in the same eight-year period from the sample of 692 members of the 50-Plus Fitness Association. $X$ is the number of people over 50 who ran and died in the same eight-year period from the sample of 692 members of the 50 -Plus Fitness Association. $P^{\prime}$ is the population proportion of people over 50 who ran and died in the same eight-year period. $X$ is the population proportion of people over 50 who ran and died in the same eight-year period from the sample of 692 members of the 50 -Plus Fitness Association. $P^{\prime}$ is the number of people over 50 who ran and died in the same eight-year period.

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Problem 431

$\checkmark 2$ 4 5 6 7 8 9 10 11 Español
Testing, testing: An instructor believes that the mean time that students will spend on the take home test is 8 hours. A test is made of $H_{0}: \mu=8$ versus $H_{1}: \mu<8$ . The null hypothesis is not rejected. State an appropriate conclusion.
There $\square$ (Choose one) enough evidence to conclude that the mean time spent is (Choose one) $\nabla 8$ hours. $\square$

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Problem 432

Test if the mean height of 5-year-olds is > $95 \mathrm{~cm}$ using a sample mean of $100 \mathrm{~cm}$ , $n=20$ , $\sigma=6 \mathrm{~cm}$ , at $\alpha=0.01$ . a) State hypotheses, b) find test statistic, c) find P-value, d) make decision, e) conclude.

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Problem 433

7.- A pro shop has a probability distribution for golf ball orders. a) Find the probability of ordering at most 2 golf balls. b) Find the probability of ordering at least one golf ball. c) Find the mean.
8.- A teacher claims the mean height of 5-year-olds is more than 95 cm. a) State the null and alternative hypothesis. b) Find the test statistic. c) Find the P-value or critical points. d) Make a decision using P-value or critical values. e) State your conclusion.

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Problem 434

Test if the proportion of men who smoke ( $p_m$ ) is greater than that of women ( $p_w$ ) using a 0.05 level. Find hypotheses, test statistic, P-value, decision, and conclusion. Also, find the $90\%$ confidence interval. Bonus: Predict $y$ for $x=32$ using $\hat{y}=5.50+1.91x$ .

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Problem 435

A songwriter studies the correlation between song length (in seconds) and weeks at number one. Use significance level 0.05 to analyze:
a) Set null and alternative hypotheses. b) Calculate $r$ , statistic value $t$ , and $p$ -value. c) Find critical values for $r$ . d) Decide using p-value or critical values.

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Problem 436

Find the $z$ -score for a person who scored 616 on an exam with mean 500 and standard deviation 40.

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Problem 437

Calculate the correlation coefficient between annual growth of National Income and Gross Domestic Saving from 1992-2002.

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Problem 438

Conjecture the percentage of the population with type O blood from a sample result of 0.42. Is it descriptive or inferential statistics?

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Problem 439

nentary Statistis (FALL 2 2024) Kerlise Sylvestre 11/21/24 8:47 PM Hypothesis Tests Question 22, 8.3.21-T HW Score: $66.23 \%$ , 19.87 of Part 2 of 4 30 points Points: 0.55 of 1 Save
Listed below are the lead concentrations (in $\mu \mathrm{g} / \mathrm{g}$ ) measured in different Ayurveda medicines. Ayurveda is a traditional medical system commonly used in India. The lead concentrations listed here are from medicines manufactured in the United States. Assume that a simple random sample has been selected. Use a 0.10 significance level to test the claim that the mean lead concentration for all such medicines is less than $14.0 \mu \mathrm{~g} / \mathrm{g}$ . 3.00 6.48 6.00 5.50 20.46 7.48 11.96 20.51 11.47 17.54
Identify the null and alternative hypotheses. $\begin{array}{l} H_{0}: \mu=14.0 \\ H_{1}: \mu<14.0 \end{array}$ (Type integers or decimals. Do not round.) Identify the test statistic $\square$ (Round to two decimal places as needed.) 23 Ive this View an example Get more help Clear all Check answer

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Problem 440

tistis (FALL 2 2024) Kerlise Sylvestre 11/21/24 8:51 PM esis Tests Question 22, 8.3.21-T HW Score: 66.23\%, 19.87 of Part 2 of 4 30 points Points: 0.55 of 1 Save
Listed below are the lead concentrations (in $\mu \mathrm{g} / \mathrm{g}$ ) measured in different Ayurveda medicines. Ayurveda is a traditional medical system commonly used in India. The lead concentrations listed here are from medicines manufactured in the United States. Assume that a simple random sample has been selected. Use a 0.10 significance level to test the claim that the mean lead concentration for all such medicines is less than $14.0 \mu \mathrm{~g} / \mathrm{g}$ . 3.00 6.48 6.00 5.50 20.46 7.48 11.96 20.51 11.47 17.54
Identify the null and alternative hypotheses. $\begin{array}{l} H_{0}: \mu=14.0 \\ H_{1}: \mu \end{array}$ (Type integers or decimals. Do not round.) Identify the test statistic. 0.94 (Raind to two decimal places as needed.)

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Problem 441

For 39 nations, a correlation of 0.886 was found between $y=$ Internet use (\%) and $x=$ gross domestic product (GDP, in thousands of dollars per capita). The regression equation is $\hat{y}=-3.56+1.69 x$ . Complete parts (a) through (c). a. Based on the correlation value, the slope had to be positive. Why? A. The slope and correlation are positive because gross domestic product could not be negative. B. The correlation and the slope are positive because the $y$ -intercept is negative. C. That is a very unusual fact, because the slope and correlation usually have different signs. D. Although slope and correlation usually have different values, they always have the same sign. b. One nation had a GDP of 38.5 thousand dollars and Internet use of $28.8 \%$ . Find its predicted Internet use based on the regression equation. 61.5 \% (Round to one decimal place as needed.) c. Find the residual for this nation. $\square$ (Round to one decimal place as needed.)

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Problem 442

Palt 1 of Points: 0.92 of 1
A simple random sample of size $n=12$ is drawn from a population that is normally distributed. The sample mean is found to be $\bar{x}=25.2$ and the sample standard deviation is found to be $s=6.6$ . Determine if the population mean is different from 28 at the $\alpha=0.10$ level of significance. Complete parts (a) through (d) below. Click here to view the standard normal distribution table (page 1). Click here to view the standard normal distribution table (page 2). Click here to view the table of critical t-values. (a) Determine the null and alternative hypotheses. $\mathrm{H}_{0}$ $\square$ $\square$ $\square$ $\mathrm{H}_{1}$ $\square$ $\square$ $\square$ (Type integers or decimals. Do not round.) kample Get more help Clear all Check answer

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Problem 443

Idow Help (6) 119; Fall 2024 Jurilyn Butler 11/21/24 8:36 PM HW - Testing HW Score: 35.56\%, 3.56 of 10 letween Means Question 2, 8.2.3 points amples, Sigma 1 Part 2 of 2 (*) Points: 0 of 1 Save known
Use the $t$ -distribution table to find the critical value(s) for the indicated alternative hypotheses, level of significance $\alpha$ , and sample sizes $n_{1}$ and $n_{2}$ . Assume that the samples are random and independent, and the populations are normally distributed. Complete parts (a) and (b). $H_{a}: \mu_{1} \neq \mu_{2}, \alpha=0.20, n_{1}=10, n_{2}=2$
Click the icon to view the $t$ -distribution table. (a) Find the critical value(s) assuming that the population variances are equal. $-1.372,1.372$ (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.) (b) Find the critical value(s) assuming that the population variances are not equal. $\square$ (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.) View an example Get more help - Clear all Chick answer

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Problem 444

Part 1 of 4 Points: 0 of 1 Save
The accompanying data set includes volumes (ounces) of a sample of cans of regular Coke. The summary statistics are $n=36, \bar{x}=12.192 \mathrm{oz}, \mathrm{s}=0.099 \mathrm{oz}$ . Assume that a simple random sample has been selected. Use a 0.01 significance level to test the claim that cans of Coke have a mean volume of 12.00 ounces. Does it appear that consumers are being cheated?
Click the icon to view the data set of regular Coke can volumes.
Identify the null and alternative hypotheses. $\mathrm{H}_{0}$ : $\square$ $\square$ $\square$ $\mathrm{H}_{1}$ : $\square$ $\square$ (Type integers or decimals. Do not round.)

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Problem 445

Use the t-distribution table to find the critical value(s) for the indicated alternative hypotheses, level of significance $\alpha$ , and sample sizes $n_{1}$ and $n_{2}$ . Assume that the samples are random and independent, and the populations are normally distributed. Complete parts (a) and (b). $H_{a}: \mu_{1}<\mu_{2}, \alpha=0.01, n_{1}=15, n_{2}=8$
E Click the icon to view the t-distribution table. (a) Find the critical value(s) assuming that the population variances are equal. $\square$ (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.)

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Problem 446

Pait 4 or 5 Points: 0 of 1 Save
Use the accompanying 200 Los Angeles commute times to test the claim that the mean Los Angeles commute time is less than 34 minutes. Assume that a simple random sample has been selected. Use a 0.01 significance level. Compare the sample mean to the claimed mean of 34 minutes. Is the difference between those two values statistically significant?
Click the icon to view the Los Angeles commute times. $-1.52$ (Round to two decimal places as needed.) Identify the P-value. 0.065 (Round to three decimal places as needed.) State the conclusion about the null hypothesis, as well as the final conclusion that addresses the original claim. $\square$ the null hypothesis. There $\square$ sufficient evidence at the 0.01 significance level to $\square$ the claim that the mean Los Angeles commute time is less than 34 minutes. ew an example Get more help - Clear all Final check

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Problem 447

A pet association claims that the mean annual costs of food for dogs and cats are the same. The results for samples or the two types of pets are shown below. At $\alpha=0.05$ , can you reject the pet association's claim? Assume the oopulation variances are equal. Assume that the samples are random and independent, and the populations are normally distributed. Complete parts (a) through (e). \begin{tabular}{|l|l|} \hline \multicolumn{1}{|c|}{ Dogs } & \multicolumn{1}{c|}{ Cats } \\ \hline $\bar{x}_{1}=\$ 257$ & $\bar{x}_{2}=\$ 230$ \\ $s_{1}=\$ 31$ & $s_{2}=\$ 27$ \\ $n_{1}=16$ & $n_{2}=17$ \\ \hline \end{tabular} D. The rejection regions are $t<-2.04$ and $t>2.04$ . (c) Find the standardized test statistic. $\mathrm{t}=2.67$ (Round to two decimal places as needed.) (d) Decide whether to reject or fail to reject the null hypothesis. $\square$ Reject the null hypothesis because the test statistic is $\square$ in a/the rejection region. (e) Interpret the decision in the context of the original claim.
At the $5 \%$ significance level, $\square$ enough evidence to $\square$ the claim that the mean annual cost of food for dogs is $\square$ the mean annual cost of food for cats.

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Problem 448

A personnel director in a particular state claims that the meanannual income is greater in one of the state's counties (county A) than it is in another county (county B). In County A, a random sample of 18 residents has a m annual income of $\$ 40,800$ and a standard deviation of $\$ 8800$ . In County B, a random sample of 8 residents has a mean annual income of $\$ 37,600$ and a standard deviation of $\$ 5800$ . At $\alpha=0.10$ , answer parts (a) through (e). Ass the population variances are not equal. If convenient, use technology to solve the problem. D. "The mean annual incomes in counties $A$ and $B$ are not equal."
What are $\mathrm{H}_{0}$ and $\mathrm{H}_{\mathrm{a}}$ ? The null hypothesis, $H_{0}$ , is $\mu_{1} \leq \mu_{2}$ . The alternative hypothesis, $H_{a}$ , is $\mu_{1}>\mu_{2}$ . Which hypothesis is the claim? The null hypothesis, $\mathrm{H}_{0}$ The alternative hypothesis, $\mathrm{H}_{\mathrm{a}}$ (b) Find the critical value(s) and identify the rejection region(s).
Enter the critical value(s) below. $\square$ (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.)

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Problem 449

A personnel director in a particular state claims that the meanannual income is greater in one of the state's counties (county A) than it is in another county (county B). In County A, a random sample of 18 residents has a mean annual income of $\$ 40,800$ and a standard deviation of $\$ 8800$ . In County B, a random sample of 8 residents has a mean annual income of $\$ 37,600$ and a standard deviation of $\$ 5800$ . At $\alpha=0.10$ , answer parts (a) through (e). Assum the population variances are not equal. If convenient, use technology to solve the problem. D. "The mean annual incomes in counties $A$ and $B$ are not equal."
What are $\mathrm{H}_{0}$ and $\mathrm{H}_{\mathrm{a}}$ ? The null hypothesis, $H_{0}$ , is $\mu_{1} \leq \mu_{2}$ . The alternative hypothesis, $H_{a}$ , is $\mu_{1}>\mu_{2}$ . Which hypothesis is the claim? The null hypothesis, $\mathrm{H}_{0}$ The alternative hypothesis, $\mathrm{H}_{\mathrm{a}}$ (b) Find the critical value(s) and identify the rejection region(s).
Enter the critical value(s) below. 1.345 (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.)

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Problem 450

A personnel director in a particular state claims that the meanannual income is greater in one of the state's counties (county A) than it is in another county (county B). In County A, a random sample of 18 residents has a me annual income of $\$ 40,800$ and a standard deviation of $\$ 8800$ . In County B, a random sample of 8 residents has a mean annual income of $\$ 37,600$ and a standard deviation of $\$ 5800$ . At $\alpha=0.10$ , answer parts (a) through (e). Assur the population variances are not equal. If convenient, use technology to solve the problem. D. "The mean annual incomes in counties $A$ and $B$ are not equal."
What are $\mathrm{H}_{0}$ and $\mathrm{H}_{\mathrm{a}}$ ? The null hypothesis, $H_{0}$ , is $\mu_{1} \leq \mu_{2}$ . The alternative hypothesis, $H_{a}$ , is $\mu_{1}>\mu_{2}$ . Which hypothesis is the claim? The null hypothesis, $\mathrm{H}_{0}$ The alternative hypothesis, $\mathrm{H}_{\mathrm{a}}$ (b) Find the critical value(s) and identify the rejection region(s).
Enter the critical value(s) below. 1.345 (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.)

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Problem 451

A personnel director in a particular state claims that the meanannual income is greater in one of the state's counties (county A) than it is in another county (county B). In County A, a random sample of 18 residents has a mear annual income of $\$ 40,800$ and a standard deviation of $\$ 8800$ . In County B, a random sample of 8 residents has a mean annual income of $\$ 37,600$ and a standard deviation of $\$ 5800$ . At $\alpha=0.10$ , answer parts (a) through (e). Assum the population variances are not equal. If convenient, use technology to solve the problem.
The alternative hypothesis, $\mathrm{H}_{\mathrm{a}}$ (b) Find the critical value(s) and identify the rejection region(s).
Enter the critical value(s) below. 1.415 (Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.)
Select the correct rejection region(s) below. A. $t<-t_{0}, t>t_{0}$ B. $t>t_{0}$ C. $t<-t_{0}$ D. $-t_{0}<t<t_{0}$

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Problem 452

For the following claim, find the null and alternative hypotheses, test statistic, critical value, and draw a conclusion. Assume that a simple random sample has been selected from a normally distributed population. Answer parts a-d.
Claim: The mean IQ score of statistics professors is greater than 128.
Sample data: $n=17, \bar{x}=131, s=11$ . The significance level is $\alpha=0.05$ . (7) Click the icon to view a table of critical t-values. $\mathrm{t}=1.124$ (Round to three decimal places as needed.) c. Find the critical value using a t-distribution table.
The critical value is $\square$ (Round to three decimal places as needed.)

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Problem 453

Question 13 of 20
Find the critical $x^{2}$ -values to test the claim $\sigma^{2}=4.3$ if $n=12$ and $\alpha=0.05$ . A. $3.053,24.725$ B. $3.816,21.920$ C. $4.575,19.675$ D. $2.603,26.757$

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Problem 454

12119; Fall 2024 Question 16 of 20 This test: 20 This questi
Find the standardized test statistic, $z$ , to test the claim that $p_{1} \neq p_{2}$ . The sample statistics listed below are from independent samy $n_{1}=1000, x_{1}=250$ , and $n_{2}=1200, x_{2}=195$ A. 2.80 B. 5.09 C. 3.21 D. 4.76

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Problem 455

Question 18 of 20 This test: 20 point(s) This question: 1 po
Find the standardized test statistic $t$ for a sample with $n=20, \bar{x}=7.9, s=2.0$ , and $\alpha=0.05$ if $H_{a}: \mu<8.3$ . Round your answer to two decim A. -1.23 B. -0.89 C. -1.27 D. -0.87

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Problem 456

(I) 119; Fall 2024 Question 19 of 20
Find the critical $x^{2}$ -value to test the claim $\sigma^{2} \leq 3.2$ if $n=20$ and $\alpha=0.01$ . A. 27.204 B. 30.144 C. 32.852 D. 36.191

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Problem 457

Question 15 of 20
Find the critical value and rejection region for the type of t-test with level of significance $\alpha$ and sample size $n$ Left-tailed test, $\alpha=0.01, n=27$ A. $t_{0}=-1.315 ; t<-1.315$ B. $t_{0}=2.479 ; t>2.479$ c. $t_{0}=-2.473 ; t<-2.473$ D. $t_{0}=-2.479 ; t<-2.479$

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Problem 458

Question 12 of 20 This test: 20 point(s) As part of a Master's thesis project, a mathematics teacher is interested in the effect learn one algebraic concept using traditional methods. Then in on another in the effects of two different teaching methods on mathematics ad Determine whether the samples are dependent or independent. independent dependent

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Problem 459

9; Fall 2024
Classify the two given samples as independent or dependent Sample 1: Pre-training weights of 29 people Sample 2: Post-training weights of 29 people independent dependent

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Problem 460

This test: ? This ques
Find the standardized test statistic, $t$ , to test the claim that $\mu_{1}>\mu_{2}$ . Two samples are randomly selected and come from populati that $\sigma_{1}^{2} \neq \sigma_{2}^{2}$ . $n_{1}=18, n_{2}=13, \bar{x}_{1}=415, \bar{x}_{2}=400, s_{1}=40, s_{2}=25$ A. 3.271 B. 1.865 C. 2.819 D. 1.282

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Problem 461

7. A Gallup poll asked random samples of Americans in 2016 and 2018 if they were satisfied with the quality of the environment. In 2016, 548 were satisfied with the quality of the environment and 430 were dissatisfied. In 2018, 477 were satisfied and 438 were dissatisfied. Determine whether the proportion of Americans who are satisfied with the quality of the environment has declined. Use a 0.05 significance level. a) Will you conduct hypotheses tests for mean or proportion? One sample or two sample? Explain. Utilize the correct variables to support your answers. conduct a propgrtiontests and a two gample (4 pts) orrection b) Clearly state the null and alternative hypotheses for the test. $\begin{array}{l} H_{0}: p_{1}=p_{2} \\ H_{A}: p_{1}>P_{2} \end{array}$ (4 pts) c) Based on the technology output given below will you reject the null hypothesis? Explain why or why not? (4 pis)
Hypothesis test results: \begin{tabular}{|l|r|r|r|r|c|c|c|c|} \hline Difference & Count1 & Total1 & Count2 & Total2 & Sample Diff & Std. Err. & Z-Stat & P-value \\ \hline $\mathrm{P}_{1}-\mathrm{P}_{2}$ & 548 & 978 & 477 & 915 & 0.039015723 & 0.022917462 & 1.7024452 & 0.0443 \\ \hline \end{tabular}
We fiwie reject the null hypothgsis Becaus e there enough why? - significant evidence why d) Write a sentence clearly stating your conclusion in the context of the problem. (5 pts)

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Problem 462

6. Data were collected on the weights of random samples of professional hockey players and professional baseball players (Source: NHL.com, MLB.com). The results are shown in the table below. \begin{tabular}{|l|l|l|} \hline & Hockey & Baseball \\ \hline \# of Players & 40 & 50 \\ \hline Mean Weight (Ibs) & 201 & 207 \\ \hline \begin{tabular}{c} Standard \\ Deviation \end{tabular} & 15 & 24 \\ \hline \end{tabular}
Is the mean weight of professional baseball players significantly greater than the mean weight of professional hockey players? Conduct a hypothesis test with a significance level of 0.05 . a) Will you conduct hypotheses tests for mean or proportion? One sample or two sample? Explain. Utilize the correct variables to support your answers. We conduct hypothesestest mean and use ativa ( 4 pts )
Sample Sample 2 Baseball 207 samplelultockey 201 std 24 std is \# of players 50 \# of Players 40 (4 pts) b) Clearly state the null and alternative hypotheses for the test. orlection $\begin{array}{l} H_{0}: u_{1}=u_{2} \text { or } u_{1}-u_{2}=0 \\ H_{A}: y<u_{2} \end{array}$ c) Based on the technology result given below will you reject the null hypothesis or not? Explain why or why not. (4pts)
Hypothesis test results: \begin{tabular}{|l|r|l|c|c|c|} \hline Difference & Sample Diff. & Std. Err & DF & TStat & P-value \\ \hline $\mu_{1}-\mu_{2}$ & -6 & 4.1406521 & 83.516558 & -1.4490471 & 0.0755 \\ \hline \end{tabular}
The $p$ -value is greater than the null hypotheg we fail toreject the nullhxpothesis $P$ -value $=0.0755>0.05$ d) Write a sentence clearly stating your conclusion in the context of the problem. (5 pts) thereis not enough evidence to

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Problem 463

(4)
5. In 2016 a poll estimated that $5.3 \%$ of American adults are vegetarian. A nutritionist thinks this rate has increased. The nutritionist samples 150 American adults and finds that 13 are vegetarian. Conduct a hypothesis test using a significance level of 0.05 . a) Clearly state the null and alternative hypotheses for the test. (4 pts) $\begin{array}{l} H_{0}: P=0.053 \\ H_{A}: P>0.053 \end{array}$ b) State the variables used to represent the sample proportion and find the sample b) $\frac{13}{150}=\frac{\text { forscces }}{\text { samplesize }}=\hat{p}$ (4 pts) c) Using the hypotheses results given below will you reject the null hypothesis or not? Explain why or why not. (4pts)
Hypotinesis test results: \begin{tabular}{|l|r|r|c|c|c|c|} \hline Proportion & Counts: & Total & Sample Prop. & Std. Err. & Z-Stat & P-value \\ \hline p & 13 & 150 & 0.086666667 & 0.018292257 & 1.8404873 & 0.0328 \\ \hline \end{tabular} $\begin{array}{l} \text { - value }=0.0328<\text { H1ph90.05 } \\ \text { reject HO } \end{array}$ reject 40 correcction d) Write a sentence clearly stating your conclusion in the context of the problem. ( 5 pts ) The nutritionist San $\quad 150$ American adults has increase d. The

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Problem 464

4. In a simple random sample of 1500 young people, $76 \%$ had earned a high school diploma. Suppose this sample is used to find that the $95 \%$ confidence interval for the the past, 7 of young people who have earned a high school diploma is $(0.738,0.782)$ . In confidence of all young people earned high school diplomas. Does the given earn high school diplomas hasdecreased? Explain. 15 claim hypothesis support the true the given enfidence interval suppor the claim that the percentaye has decreased $76 \%$ . thein yh the past $79 \%$ . of all young people.
3. The U.S. Department of Health has suggested that a healthy total cholesterol measurement should be $200 \mathrm{mg} / \mathrm{dL}$ or less. Records from 50 randomly and independently selected people from a study showed a sample mean of $208.61 \mathrm{mg} / \mathrm{dL}$ and a standard deviation of $39.52 \mathrm{mg} / \mathrm{dL}$ . Test the hypothesis that the mean cholesterol level is more than $200 \mathrm{mg} / \mathrm{dL}$ using a significance level of 0.05 . a) Clearly state the null and alternative hypotheses for the test. (4 pts) $\begin{array}{l} H_{0}: u=200 \\ H_{A}: u>200 \mathrm{~V} \end{array}$ b) Technology output for the test is given below. State the $t$ -stat and $p$ -value (Round to 3 decimal places). (2 pts) c) Based on your results from part (b) will you reject the null hypgthesis or not? Explain why or why apo. ( 4 pts ) (5 pls) d) Write a sentence clearly stating your conclusion in the context of the problem.

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Problem 465

Use the sample data and confidence level given below to complete parts (a) through (d). A drug is used to help prevent blood clots in certain patients. In clinical trials, among 4997 patients treated with the drug, 114 developed the adverse reaction of nausea. Construct a $90 \%$ confidence interval for the proportion of adverse reactions. a) Find the best point estimate of the population proportion p . 0.023 (Round to three decimal places as needed.) b) Identify the value of the margin of error E . $E=0.003$ (Round to three decimal places as needed.) c) Construct the confidence interval. $0.020<p<0.026$ (Round to three decimal places as needed.) d) Write a statement that correctly interprets the confidence interval. Choose the correct answer below. A. One has $90 \%$ confidence that the sample proportion is equal to the population proportion. B. There is a $90 \%$ chance that the true value of the population proportion will fall between the lower bound and the upper bound. C. One has $90 \%$ confidence that the interval from the lower bound to the upper bound actually does contain the true value of the population proportion. D. $90 \%$ of sample proportions will fall between the lower bound and the upper bound.

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Problem 466

What percent of millennials and Gen Z shoppers have shopped for secondhand apparel according to a 2022 ThredUp report? $\square$ about 37\% over 40\% about 25\% under 20\%
Rewfich Submit

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Problem 467

the interest earned at account's maturity (in 18 years from opening).
7. Currently, the density of Earth's human population $D$ is about 65 people per square kilometre, or about 1 person per 15,384 square metres. The current population growth rate $p$ is about 1 percent per year (This roughly corresponds to every family having on average three children.). Find the population density expected in one thousand years from now if the growth rate does not change.

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Problem 468

6. (16 points) In a random survey of 900 licensed drivers aged 16 and over, $32 \%$ of those respondents reported that they make angry gestures while driving. Use a 0.05 significance level to test the claim that among licensed drivers aged 16 and over, the percentage who make angry gestures while driving is $30 \%$ . Identify the null hypothesis, alternative hypothesis, test statistic, critical value or P -value, and conclusion about the null hypothesis. Use the normal distribution as an approximation of the binomial distribution.

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Problem 469

Find the weighted estimate, $\bar{p}$ , to test the claim that $p_{1}<p_{2}$ . Use $\alpha=0.10$ . The sample statistics listed below are from independent samples $n_{1}=550, x_{1}=121$ , and $n_{2}=690, x_{2}=195$ A. 0.255 B. 1.116 C. 0.730 D. 0.338

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Problem 470

Determine whether the normal sampling distribution cain be used. The claim is $p<0.015$ and the sample size is $n=150$ . Use the normal distribution. Do not use the normal distribution.

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Problem 471

1. University and Community College: A Savannah at a four-year college claims that mean enrollment at four-year colleges is higher than at two-year colleges in the United States. Two surveys are conducted. Of the 35 two-year colleges surveyed, the mean enrollment was 5,068 with a standard deviation of 4,777 . Of the 35 four-year colleges surveyed, the mean enrollment was 5,466 with a standard deviation of 8,191. a. $H_{0}$ : b. $H_{a}$ : c. Test statistic: d. $P$ -value:

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Problem 472

ALL 2 2024) Kerlise Sylvestre nference Homework Question 4, 9.1.11-T HW Score: 10.94\%, 2.63 of 24 points Part 5 of 7 Points: 0 of 1 Save
A study was conducted to determine the proportion of people who dream in black and white instead of color. Among 315 people over the age of 55,68 dream in black and white, and among 292 people under the age of 25,13 dream in black and white. Use a 0.01 significance level to test the claim that the proportion of people over 55 who dream in black and white is greater than the proportion for those under 25. Complete parts (a) through (c) below. $\mathrm{H}_{1}: \mathrm{P}_{1}<\mathrm{P}_{2}$ $H_{1}: p_{1}>p_{2}$ $H_{1}: P_{1} \mp P_{2}$
Identify the test statistic. $z=6.21$ (Round to two decimal places as needed.) Identify the P -value. $P \text {-value }=0.000$ (Round to three decimal places as needed.) What is the conclusion based on the hypothesis test? The P -value is less than $\square$ reject the null hypothesis. There is $\square$ evidence to support the claim that the proportion of people over 55 who dream in black and white is greater than the proportion for those under 25. b. Test the claim by constructing an appropriate confidence interval. $\square$ The $98 \%$ confidence interval is $\square<\left(p_{1}-p_{2}\right)<\square$ . (Round to three decimal places as needed.) Clear all Check answer $12: 47$ PM 11/22/2024

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Problem 473

The Gazelles are a professional soccer team based in a large city. At the team's home matches, children's admission is half-off. At the last home match, 23 out of every 47 attendees were children. At that match, the facilities manager took a sample of the attendees. He found that 44 of the 73 attendees in his sample were children. For the facilities manager's sample, find and write with proper notation the population proportion and sample proportion of attendees who were children. Write the proportions as decimals (not percentages) rounded to two decimal places. (a) Population proportion: (Choose one) $\nabla=$ $\square$ (b) Sample proportion: (Choose one) $\nabla=$ $\square$

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Problem 474

iample Inference Homework Question 6, 9.1.16-T HW Score: $11.53 \%, 4.21$ or $\angle 4$ points Save Part 2 of 7 Points: 0 of 1
In a randomized controlled trial, insecticide-treated bednets were tested as a way to reduce malaria. Among 344 infants using bednets, 14 developed malaria. Among 283 infants not using bednets, 33 developed malaria. Use a 0.01 significance level to test the claim that the incidence of malaria is lower for infants using bednets. a. Test the claim using a hypothesis test. b. Test the claim by constructing an appropriate confidence interval. c. Based on the results, do the bednets appear to be effective? A. $H_{0} \cdot \mu_{1}<\mu_{2}$ $\mathrm{H}_{1} \cdot \mathrm{p}_{1}<\mathrm{p}_{2}$ D. $H_{0}: p_{1}=p_{2}$ $H_{1}: p_{1}>p_{2}$ $H_{1}: p_{1}>p_{2}$ E. $\mathrm{H}_{0}: \mathrm{P}_{1}=\mathrm{p}_{2}$ $H_{1}: p_{1}<p_{2}$
$U_{0} \cdot \mu_{1}-\mu_{2}$ $H_{1}: p_{1} \neq p_{2}$ F. $H_{0}: p_{1} \neq p_{2}$ $H_{1}: p_{1}=p_{2}$
Identify the test statistic. $\square$ (Round jo two decimal places as needed.)

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Problem 475

Question 11 5 pts
A professor would like to test the hypothesis that the average number of minutes that a student needs to complete a statistics exam is equal to 45 minutes. The correct hypothesis statement would be $H_{0}: \mu \neq 45$ $H_{1}: \mu=45$ . $H_{0}: \mu=45$ $H_{1}: \mu \neq 45$ . $H_{0}-\mu=45$ $\mathrm{H}_{1}: \mu>45$ . $\mathrm{H}_{0}: \mu=45$ $\mathrm{H}_{1}: \mu<45 .$

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Problem 476

An elementary school claims that the standard deviation in reading scores of its fourth grade students is less than 4.35. Determine whether the hypothesis test is right-tailed, left-tailed, or two-tailed.

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Problem 477

The statement represents a claim. Write its complement and state which is $\mathrm{H}_{0}$ and which is $\mathrm{H}_{A}$ . $\mu=8.1$ A. $H_{0}: \mu=8.1$ (claim); $H_{a}: \mu \neq 8.1$ B. $H_{0}: \mu \leq 8.1 ; H_{a}: \mu>8.1$ (claim) C. $H_{0}: \mu \geq 8.1$ (claim); $H_{a}: \mu<8.1$ D. $H_{0}: \mu \neq 8.1 ; H_{a}: \mu=8.1$ (claim)

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Problem 478

Question 14 of 20 11/22/24 1:13 PM This test: 20 point(s) possible This question: 1 point(s) possible
As part of a marketing experiment, a department store regularly mailed discount coupons to 25 of its credit card holders. Their total credit card purchases over the next three months were or to the credit card purchases over the next three months for 25 credit card holders who were not sent discount coupons. Determine whether the samples are dependent or independent. independent dependent

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Problem 479

Part 6 of 10 Points: 0.27 of 1 Save patients suffer from headaches? Assume the samples are random and dependent, and the population is normally distributed. Complete parts (a) through ( $f$ ). \begin{tabular}{|l|c|c|c|c|c|c|c|c|c|c|c|} \hline Patient & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 \\ \hline Daily headache hours (before) & 2.1 & 4.2 & 2.2 & 3.6 & 2.2 & 3.2 & 2.5 & 4.1 & 3.6 & 3.9 & 4.1 \\ \hline Daily headache hours (after) & 1.3 & 4.6 & 1.6 & 1.3 & 1.4 & 2.5 & 2.4 & 4.0 & 1.5 & 3.4 & 4.8 \\ \hline \end{tabular} (a) Identify the claim and state $\mathrm{H}_{0}$ and $\mathrm{H}_{\mathrm{a}}$
The claim is "The therapy helps to reduce the length of time patients suffer from headaches." Let $\mu_{d}$ be the hypothesized mean of the patients' daily headache hours before therapy minus their daily headache hours after it. State $\mathrm{H}_{0}$ and $\mathrm{H}_{\mathrm{a}}$ . Choose the correct answer below. A. $H_{0}: \mu_{d} \geq \bar{d}$ B. $H_{0}: \mu_{d}=\bar{d}$ c. $\mathrm{H}_{0}: \mu_{\mathrm{d}} \leq 0$ $\mathrm{H}_{\mathrm{a}}: \mathrm{H}_{\mathrm{d}}<\overline{\mathrm{d}}$ $\mathrm{H}_{\mathrm{a}}: \mu_{\mathrm{d}} \neq \overline{\mathrm{d}}$ $H_{a}: \mu_{d}>0$ D. $H_{0}: \mu_{d} \leq \bar{d}$ E. $H_{0} \quad \mu_{d} \geq 0$ F. $H_{0} \cdot \mu_{d} \neq \bar{d}$ $\mathrm{H}_{\mathrm{a}}: \mu_{\mathrm{d}}>\overline{\mathrm{d}}$ $H_{a}: \mu_{d}<0$ $\mathrm{H}_{\mathrm{a}}: \mu_{\mathrm{d}}=\overline{\mathrm{d}}$ (b) Find the critical value(s) and identify the rejection region(s). $t_{0}=2.764$ (Use a comma to separate answers as needed. Type an integer or a decimal. Round to three decimal places as needed.) Identify the rejection region(s). Choose the correct answer below. A. $\mathrm{t}<-3.169$ or $1>3.169$ B. $i<-2.764$ or $\$>2.764$ C. $1>2764$ D. $i<-3.169$ (c) Calculate $\bar{d}$ $\bar{d}=627$ (Type an integer or a decimal. Round to three decimal places as needed.) Calculate $\mathrm{s}_{\mathrm{d}}$ $\square$ (Type an integer or a decimal. Round to three decimal places as needed.)

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Problem 480

Find the critical values, $t_{0}$ , to test the claim that $\mu_{1}=\mu_{2}$ . Two samples are randomly Submit test $\sigma_{1}^{2} \neq \sigma_{2}^{2}$ . Use $\alpha=0.05$ . $n_{1}=25, n_{2}=30, \bar{x}_{1}=16, \bar{x}_{2}=14, s_{1}=1.5, s_{2}=1.9$ A. $\pm 2.064$ B. $\pm 2.797$ $\pm 1.711$ $\pm 2.492$

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Problem 481

```latex A sleep disorder specialist wants to test the effectiveness of a new drug that is reported to increase the number of hours of sleep patients get during the night. To do so, the specialist randomly selects 16 patients and records the number of hours of sleep each gets with and without the new drug. The accompanying table shows the results of the two-night study. Construct a $90\%$ confidence interval for $\mu_{\mathrm{d}}$ , using the inequality $\overline{\mathrm{d}}-\mathrm{t}_{\mathrm{c}} \frac{\mathrm{S}_{\mathrm{d}}}{\sqrt{n}}<\mu_{\mathrm{d}}<\overline{\mathrm{d}}+\mathrm{t}_{\mathrm{c}} \frac{\mathrm{S}_{\mathrm{d}}}{\sqrt{n}}$ . Assume the populations are normally distributed.
Calculate $d$ for each patient by subtracting the number of hours of sleep with the drug from the number without the drug. The confidence interval is $\square$ $\mathrm{hr}<\mu_{\mathrm{d}}<$ $\square$ hr. (Round to two decimal places as needed.)
The data on hours of sleep with and without the drug is as follows:
\begin{tabular}{|l|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|} \hline Patient & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 & 13 & 14 & 15 & 16 \\ \hline \begin{tabular}{l} Hours of \\ sleep (without \\ the drug) \end{tabular} & 3.1 & 2.7 & 4.5 & 4.4 & 1.9 & 2.4 & 2.8 & 3.4 & 3.5 & 3.6 & 2.8 & 1.9 & 4.6 & 5.1 & 2.2 & 2.1 \\ \hline \begin{tabular}{l} Hours of \\ sleep (using \\ the drug) \end{tabular} & 3.8 & 4.4 & 5.4 & 6.3 & 2.6 & 3.3 & 4.1 & 5.5 & 5.3 & 5.8 & 3.5 & 4.1 & 5.3 & 6.5 & 4.6 & 4.5 \\ \hline \end{tabular} ```

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Problem 482

A fine dining restaurant claims that the group sizes of their customers follows the following distribution: \begin{tabular}{|c|c|c|c} \hline 2 people & 3 people & 4 people & $4+$ people \\ \hline $36 \%$ & $10 \%$ & $17 \%$ & $37 \%$ \end{tabular}
Gustavo, a waiter at the restaurant, would like to test this claim. He takes a sample of 93 customers and records the observed frequencies in the following table: \begin{tabular}{|c|c|c|c} 2 people & 3 people & 4 people & $4+$ people \\ \hline 35 & 2 & 21 & 35 \end{tabular} (a) In performing this statistical test, state the hypotheses. - Ho: the distribution of customers for each group is the same as the observed frequencies vs. Ha: the distribution of customers for each group is not the same as the observed frequencies Ho: the distribution of customers for each group is not the same as claimed by the restaurant vs. Ha: the distribution of customers for each group is the same as claimed by the restaurant Ho: the distribution of customers for each group is the same as claimed by the restaurant vs. Ha: the distribution of customers for each group is not the same as claimed by the restaurant Ho: the distribution of customers for each group is not the same as the observed frequencies vs. Ha: the distribution of customers for each group is the same as the observed frequencies Ho: the proportions of customers for each group are all the same vs. Ha: the proportions of customers for each group are not all the same

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Problem 483

This question: 1 point(s) possible Submit quíz
A researcher wishes to estimate the average blood alcohol concentration (BAC) for drivers involved in fatal accidents who are found to have positive BAC values. He randomly selects records from 75 such drivers in 2009 and determines the sample mean BAC to be $0.169 \mathrm{~g} / \mathrm{dL}$ with a standard deviation of $0.010 \mathrm{~g} / \mathrm{dL}$ . Use StatCrunch to complete parts (a) through (d). A. The sample size is likely greater than $5 \%$ of the population. B. The sample size is likely greater than $10 \%$ of the population. C. The sample size is likely less than $5 \%$ of the population. D. The sample size is likely less than $10 \%$ of the population. (c) Determine and interpret a 90\% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC.
Select the correct choice and fill in the answer boxes to complete your choice. (Use ascending order. Round to three decimal places as needed.) A. There is a $\square$ \% probability that the population mean BAC is between $\square$ and $\square$ for drivers involved in fatal accidents who have a positive BAC value. B. The researcher is $\square$ $\%$ confident that the population mean BAC is not between $\square$ and $\square$ for drivers involved in fatal accidents who have a positive BAC value. C. The researcher is $\square$ \% confident that the population mean BAC is between $\square$ and $\square$ for drivers involved in fatal accidents who have a positive BAC value. (d) All areas of the country use a BAC of $0.09 \mathrm{~g} / \mathrm{dL}$ as the legal intoxication level. Is it possible that the mean BAC of all drivers involved in fatal accidents who are found to have positive BAC values is less than the legal intoxication level? Explain. Choose the correct answer. A. While the target value lies within the confidence interval, since it is less than the sample mean, it is unlikely that it is the true population mean. B. Not only is it possible that the population mean is not captured in the confidence interval, in this case, it is quite likely. C. Since the target value lies within the confidence interval, it is certainly a plausible value for the population mean. D. While it is possible that the population mean is not captured in the confidence interval, it is not likely.

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Problem 484

Would you Fail to Reject $\mathrm{H}_{\mathrm{O}}$ , or Reject $\mathrm{H}_{\mathrm{O}}$ and Accept $\mathrm{H}_{1}$ under the following conditions?
Critical value is 2.06 and -2.06 Test statistic is -2.09

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Problem 485

Put the following P-values in order from weakest to strongest in terms of evidence against the statement in the null hypothesis. A. 0.013 B. 0.048 C. 0.008 D. 0.036
The correct order is $\square$ $\square$ $\square$ $\square$

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Problem 486

The Health Department states the mean pregnancy term is 8.60 months. You conduct a study of 35 women in the Reedley area and find the mean pregnancy term is 8.68 months and a sample standard deviation of 0.2 months. Using a .01 level of significance, can you conclude that the mean pregnancy term in Reedley is different than 8.6 months?
Be sure to include all of the sections listed below. Use the picture provided to choose how your curve should look and be labeled.
State $\mathrm{H}_{0}$ and $\mathrm{H}_{1}$ . Use the picture and tell me the letter of the curve that should be used. State your critical value(s). Find the test statistic.

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Problem 487

Sydnel Thomas $11 / 22 / 244.00 \mathrm{PM}$ Question 5 of 20 mileste20 pint(0) possiblo Thil question $\mathrm{I}_{\text {polnt(s) possib- }}$ Submil test
Find the standardized lest statistic, $L$ , to test the claim that $\mu_{1}>\mu_{2}$ . Two samples are randomly selected and come from populations that are normat. The samplo statistics are given below Aasume that $\sigma_{1}^{2} \neq \sigma_{2}^{2}$ . $n_{1}=18, n_{2}=13, \bar{x}_{1}=485, \bar{x}_{2}=470, s_{1}=40, s_{2}=25$

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Problem 488

Guestion 8 of 80 This topti 20 pointo paspole Suborif the $\sigma_{1}^{2}=\sigma_{2}^{2}$ . Use a 0 o 0s $n_{1}=14, n_{2}=12, x_{1}=17, x_{2}=18, x_{1}=2.5,3_{2}=2.8$

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Problem 489

\begin{table}[h] \centering \begin{tabular}{|c|c|c|c|c|c|} \hline \text{Price in Dollars} & 27 & 31 & 36 & 41 & 44 \\ \hline \text{Number of Bids} & 4 & 5 & 6 & 7 & 10 \\ \hline \end{tabular} \caption{Table of list price and number of bids for items sold through online auctions} \end{table}
Using this data, consider the equation of the regression line, $\hat{y}=b_{0}+b_{1} x$ , for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.
Step 4 of 6: Determine the value of the dependent variable $\hat{y}$ at $x=0$ .
\textbf{Answer:}
\textbf{Previous step answers:}
$b_{0}$
$b_{1}$
$x$
$y$

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Problem 490

One of the steps involved in the processing of corn flakes for cereals involves toasting the flakes. The accompanying table contains data for corn flakes thickness in millimeters for four different toasting times in seconds. Complete parts through (d) below. Click here to view the data on corn flake thickness. Click here to view a partial table of critical values of the Studentized Range, Q. a. At the 0.05 level of significance, is there evidence of a difference in the mean thickness of the corn flakes for the different toasting times?
Determine the hypotheses. Choose the correct answer below. A. $H_{0}: \mu_{1}=\mu_{2}=\cdots=\mu_{4}$ B. $H_{0}: \mu_{1}=\mu_{2}=\cdots=\mu_{3}$ $\mathrm{H}_{1}$ : Not all $\mu_{\mathrm{j}}$ are equal (where $\mathrm{j}=1,2, \ldots, 4$ ) $H_{1}$ : Not all $\mu_{j}$ are equal (where $j=1,2, \ldots, 3$ ) C. $H_{0}: \mu_{1}=\mu_{2}=\cdots=\mu_{4}$ D. $H_{0}: \mu_{1}=\mu_{2}=\cdots=\mu_{3}$ $H_{1}: \mu_{1} \neq \mu_{2} \neq \cdots \neq \mu_{4}$ $H_{1}: \mu_{1} \neq \mu_{2} \neq \cdots \neq \mu_{3}$

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Problem 491

Students were surveyed on video game time and test averages. Is the correlation negative or weak? True/False statements provided.

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Problem 492

Analyze the frequency table of art styles to determine if there's an association between art type and style.

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Problem 493

A city inspector found that $41.1\%$ of 500 buildings met readiness conditions with a margin of error of $\pm 5\%$ . What must be true?

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Problem 494

Points: 0.94 of 1 Save
According to a certain government traffic safety agency for a large country, the proportion of fatal traffic accidents in the country in which the driver had a positive blood alcohol concentration (BAC) is 0.35 . Suppose a random sample of 104 traffic fatalities in a certain region with a large population results in 44 that involved a positive BAC. Does the sample evidence suggest that the region has a higher proportion of traffic fatalities involving a positive BAC than the country at the $\alpha=0.1$ level of significance? Click here to view the standard normal distribution table (page 1). Click here to view the standard normal distribution table (page 2).
Start by determining whether the conditions for this hypothesis test are satisfied. Because $\mathrm{np}_{0}\left(1-\mathrm{p}_{0}\right)=23.7>10$ , the sample size is less than $5 \%$ of the population size, and the sample for testing the hypothesis about the population proportion (Round to one decimal place as needed.) are satisfied. is given to be random, $\square$ the requirements
What are the null and alternative hypotheses? $\mathrm{H}_{0}$ : $\square$ $\square$ versus $\mathrm{H}_{1}$ : $\square$ $>$ 0.35 (Type integers or decimals. Do not round.) Find the test statistic, $z_{0}$ . $z_{0}=$ $\square$ (Round to two decimal places as needed.)

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Problem 495

Question 5, 10.1.13 Part 1 of 5 HW Score: $57.14 \%, 4$ of 7 points Points: 0 of 1 Save
For students who first enrolled in two-year public institutions in a recent semester, the proportion who earned a bachelor's degree within six years was 0.393 . The president of a certain junior college believes that the proportion of students who enroll in her institution have a lower completion rate. (a) State the null and alternative hypotheses in words. (b) State the null and alternative hypotheses symbolically. (c) Explain what it would mean to make a Type I error. (d) Explain what it would mean to make a Type II error. (a) State the null hypothesis in words. Choose the correct answer below. A. Among students who enroll at the certain junior college, the completion rate is less than 0.393. B. Among students who enroll at the certain junior college, the completion rate is greater than 0.393. C. Among students who enroll at the certain junior college, the completion rate is 0.393 . D. Among students who first enroll in two-year public institutions, the completion rate is 0.393 .

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Problem 496

Changing jobs: A sociologist sampled 214 people who work in computer-related jobs, and found that 44 of them have changed jobs in the past 6 months.
Part: $0 / 2$
Part 1 of 2 (a) Construct a $99.8 \%$ confidence interval for those who work in computer-related jobs who have changed jobs in the past 6 months. Round the answer to at least three decimal places. A $99.8 \%$ confidence interval for the proportion of those who work in computer-related jobs who have changed jobs in the past 6 months is $\square$ $<p<$ $\square$ .

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Problem 497

Find the critical values for a $95 \%$ confidence interval using the chi-square distribution with 20 degrees of freedom. Round the answers to three decimal places.
The critical values are $\square$ and $\square$ .

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Problem 498

IQ scores: Scores on an IQ test are normally distributed. A sample of 8 IQ scores had standard deviation $s=6$ . (a) Construct a $95 \%$ confidence interval for the population standard deviation $\sigma$ . Round the answers to at least two decimal places. (b) The developer of the test claims that the population standard deviation is $\sigma=7$ . Does this confidence interval contradict this claim? Explain.
Part: $0 / 2$
Part 1 of 2
A $95 \%$ confidence interval for the population standard deviation is $\square$ $<\sigma<$ $\square$ .

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Problem 499

Points: 0 of 1 Save
The standard deviation in the pressure required to open a certain valve is known to be $\sigma=1,4 \mathrm{psi}$ . Due to changes in the manufacturing process, the quality-control manager feels that the pressure variability has increased. (a) State the null and alternative hypotheses in words. (b) State the null and alternative hypotheses symbolically. (c) Explain what it would mean to make a Type I error. (d) Explain what it would mean to make a Type II error. B. The standard deviation in the pressure required to open a certain valve is greater than 1.4 psi. C. The standard deviation in the pressure required to open a certain valve is different from 1.4 psi . D. The standard deviation in the pressure required to open a certain valve is 1.4 psi .
State the alternative hypothesis in words. Choose the correct answer below. A. The standard deviation in the pressure required to open a certain valve is different from 1.4 psi. B. The standard deviation in the pressure required to open a certain valve is 1.4 psi . C. The standard deviation in the pressure required to open any valve is 1.4 psi . D. The standard deviation in the pressure required to open a certain valve is greater than 1.4 psi . (b) State the hypotheses symbolically. $\mathrm{H}_{0}$ : $\square$ $=$ 1.4 psi $H_{1}$ : $\sigma$ $>$ 1.4 psi (Type integers or decimals. Do not round.) (c) What would it mean to make a Type I error?
The manager $\square$ the hypothesis that the pressure variability is $\square$ $\square$ psi , when the true pressure variability is $\square$ $\square$ psi. (Type integers or decimals. Do not round.)

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Problem 500

11 12 13
Coffee: The National Coffee Association reported that $65 \%$ of U.S. adults drink coffee daily. A random sample of 300 U.S. adults is selected. Round your answers to at least four decimal places as needed.
Part 1 of 6 (a) Find the mean $\mu_{p}$ .
The mean $\mu_{\hat{p}}$ is 0.65 .
Part 2 of 6 (b) Find the standard deviation $\sigma_{\hat{p}}$ .
The standard deviation $\sigma_{\hat{p}}$ is 0.0275 .
Part 3 of 6 (c) Find the probability that more than $66 \%$ of the sampled adults drink coffee daily.
The probability that more than $66 \%$ of the sampled adults drink coffee daily is 0.3564 .
Part 4 of 6 (d) Find the probability that the proportion of the sampled adults who drink coffee daily is between 0.57 and 0.71 .
The probability that the proportion of the sampled adults who drink coffee daily is between 0.57 and 0.71 is 0.9836 . Part: $5 / 6$
Part 6 of 6 (f) Using a cutoff of 0.05 , would it be unusual if less than $63 \%$ of the sampled adults drink coffee daily? it $\square$ (Choose one) $\mathbf{V}$ be unusual if less than $63 \%$ of the sampled adults drink coffee daily, since the probability is $\square$ would would not

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Statistical Inference

Problem 401

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Problem 414

Compute the correlation coefficient. \begin{tabular}{c|ccccccc} xxx & 27 & 24 & -7 & 39 & 11 & 15 & -9 \\ \hlineyyy & 11 & -7 & 12 & -9 & 21 & 8 & -4 \end{tabular}The correlation coefficient is r=r=r= □\square□ Round the answer to three decimal places as needed.

Problem 415

Select the appropriate word or phrase to complete each sentence.Part: 0 / 2 □\square□Part 1 of 2If the correlation coefficient is equal to 0 , the slope of the least-squares regression line will be equal to □\square□ (Choose one) .

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Problem 424

Compute r, the correlation coefficient, using the following data. \begin{tabular}{|c|c|c|c|c|c|c|} \hline x\mathbf{x}x & 8 & 2 & 6 & 7 & 5 & 1 \\ \hline y\mathbf{y}y & 1 & 7 & 3 & 2 & 5 & 9 \\ \hline \end{tabular} r=□r=\squarer=□ (Round to two decimal places.)

Problem 425

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Problem 427

3. You want to determine if there are differences in the caloric content of the different types of hot dogs (beef vs. mixed meat vs. vegetarian). d) What alpha level would you use with your previously selected statistical test? 0.05 0.017 0.5 0.17

Problem 428

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Problem 432

Test if the mean height of 5-year-olds is > 95 cm95 \mathrm{~cm}95 cm using a sample mean of 100 cm100 \mathrm{~cm}100 cm, n=20n=20n=20, σ=6 cm\sigma=6 \mathrm{~cm}σ=6 cm, at α=0.01\alpha=0.01α=0.01. a) State hypotheses, b) find test statistic, c) find P-value, d) make decision, e) conclude.

Problem 433

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Problem 436

Find the zzz-score for a person who scored 616 on an exam with mean 500 and standard deviation 40.

Problem 437

Calculate the correlation coefficient between annual growth of National Income and Gross Domestic Saving from 1992-2002.

Problem 438

Conjecture the percentage of the population with type O blood from a sample result of 0.42. Is it descriptive or inferential statistics?

Problem 439

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Problem 456

(I) 119; Fall 2024 Question 19 of 20Find the critical x2x^{2}x2-value to test the claim σ2≤3.2\sigma^{2} \leq 3.2σ2≤3.2 if n=20n=20n=20 and α=0.01\alpha=0.01α=0.01. A. 27.204 B. 30.144 C. 32.852 D. 36.191

Problem 457

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Problem 459

9; Fall 2024Classify the two given samples as independent or dependent Sample 1: Pre-training weights of 29 people Sample 2: Post-training weights of 29 people independent dependent

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Problem 466

What percent of millennials and Gen Z shoppers have shopped for secondhand apparel according to a 2022 ThredUp report? □\square□ about 37\% over 40\% about 25\% under 20\%Rewfich Submit

Problem 467

Problem 468

Compute the correlation coefficient. \begin{tabular}{c|ccccccc} $x$ & 27 & 24 & -7 & 39 & 11 & 15 & -9 \\ \hline $y$ & 11 & -7 & 12 & -9 & 21 & 8 & -4 \end{tabular}
The correlation coefficient is $r=$ $\square$ Round the answer to three decimal places as needed.

Select the appropriate word or phrase to complete each sentence.
Part: 0 / 2 $\square$
Part 1 of 2
If the correlation coefficient is equal to 0 , the slope of the least-squares regression line will be equal to $\square$ (Choose one) .

Compute r, the correlation coefficient, using the following data. \begin{tabular}{|c|c|c|c|c|c|c|} \hline $\mathbf{x}$ & 8 & 2 & 6 & 7 & 5 & 1 \\ \hline $\mathbf{y}$ & 1 & 7 & 3 & 2 & 5 & 9 \\ \hline \end{tabular} $r=\square$ (Round to two decimal places.)

Test if the mean height of 5-year-olds is > $95 \mathrm{~cm}$ using a sample mean of $100 \mathrm{~cm}$ , $n=20$ , $\sigma=6 \mathrm{~cm}$ , at $\alpha=0.01$ . a) State hypotheses, b) find test statistic, c) find P-value, d) make decision, e) conclude.

Find the $z$ -score for a person who scored 616 on an exam with mean 500 and standard deviation 40.

(I) 119; Fall 2024 Question 19 of 20
Find the critical $x^{2}$ -value to test the claim $\sigma^{2} \leq 3.2$ if $n=20$ and $\alpha=0.01$ . A. 27.204 B. 30.144 C. 32.852 D. 36.191

9; Fall 2024
Classify the two given samples as independent or dependent Sample 1: Pre-training weights of 29 people Sample 2: Post-training weights of 29 people independent dependent

What percent of millennials and Gen Z shoppers have shopped for secondhand apparel according to a 2022 ThredUp report? $\square$ about 37\% over 40\% about 25\% under 20\%
Rewfich Submit

Determine whether the normal sampling distribution cain be used. The claim is $p<0.015$ and the sample size is $n=150$ . Use the normal distribution. Do not use the normal distribution.