Math  /  Data & Statistics

Question4. In a simple random sample of 1500 young people, 76%76 \% had earned a high school diploma. Suppose this sample is used to find that the 95%95 \% confidence interval for the the past, 7 of young people who have earned a high school diploma is (0.738,0.782)(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%76 \%. thein yh the past 79%79 \%. of all young people.
3. The U.S. Department of Health has suggested that a healthy total cholesterol measurement should be 200mg/dL200 \mathrm{mg} / \mathrm{dL} or less. Records from 50 randomly and independently selected people from a study showed a sample mean of 208.61mg/dL208.61 \mathrm{mg} / \mathrm{dL} and a standard deviation of 39.52mg/dL39.52 \mathrm{mg} / \mathrm{dL}. Test the hypothesis that the mean cholesterol level is more than 200mg/dL200 \mathrm{mg} / \mathrm{dL} using a significance level of 0.05 . a) Clearly state the null and alternative hypotheses for the test. (4 pts) H0:u=200HA:u>200 V\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 tt-stat and pp-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.

Studdy Solution

STEP 1

1. We have a sample of 1500 young people, with 76% having earned a high school diploma.
2. The past percentage of young people earning a high school diploma was 79%.
3. A 95% confidence interval for the current percentage is given as (0.738, 0.782).
4. We are testing if the current percentage has decreased from the past 79%.
5. We have a separate hypothesis test regarding cholesterol levels with a sample mean of 208.61 mg/dL and a standard deviation of 39.52 mg/dL.

STEP 2

1. Analyze the confidence interval for high school diplomas.
2. Formulate and test the hypothesis for cholesterol levels.
3. Interpret the results and draw conclusions.

STEP 3

Determine if the confidence interval supports the claim that the percentage of young people earning a high school diploma has decreased from 79%.
The given confidence interval is (0.738, 0.782). Since 79% (0.79) is not within this interval, it suggests that the current percentage is likely lower than 79%.

STEP 4

Formulate the null and alternative hypotheses for the cholesterol level test:
H0:μ=200mg/dLH_0: \mu = 200 \, \text{mg/dL} HA:μ>200mg/dLH_A: \mu > 200 \, \text{mg/dL}

STEP 5

Identify the t-statistic and p-value from the technology output. Assume the output provides:
- t-statistic=1.53 t \text{-statistic} = 1.53 - p-value=0.065 p \text{-value} = 0.065

STEP 6

Decide whether to reject the null hypothesis based on the p-value.
Since the p-value (0.065) is greater than the significance level (0.05), we do not reject the null hypothesis.

STEP 7

Write a conclusion for each analysis:
For the high school diploma analysis: "The confidence interval suggests that the percentage of young people earning a high school diploma has decreased from the past 79%."
For the cholesterol level analysis: "There is not enough evidence to conclude that the mean cholesterol level is more than 200 mg/dL at the 0.05 significance level."

Was this helpful?

Studdy solves anything!

banner

Start learning now

Download Studdy AI Tutor now. Learn with ease and get all help you need to be successful at school.

ParentsInfluencer programContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord