Question5) "A survey asked 1500 American citizens whether they had suffered from food poisoning in the past year. There were 227 survey participants who responded "Yes". Determine a 95\% confidence interval for the probability that a randomly-chosen American has suffered from food poisoning in the past year." 6) "In a sample of 100 members at a certain gym, these members exercised on average 4.2 hours per week with a standard deviation of 0.8 hours. Write a $99 \%$ confidence interval for the amount of exercise hours per week for members at this gym." 7) "A professor believes that the average cost of a textbook is $\$ 175$. She samples 50 textbooks and determines the average price of those books to be $\$ 180$ with a standard deviation of $\$ 40$. Test her hypothesis at a confidence level of $90 \%$."