Question

Use the following information for questions 11-20: The average cholesterol level in the general US population is 189 mg/dL. A researcher wants to see if the average cholesterol for men in the US is different from 189 mg/dL. She takes a sample of 81 American males and finds a sample mean of 194 mg/dL and a sample standard deviation of 10.4. Create a 99.8% confidence interval for the true average cholesterol level of the general US male population.

11.What is the 99.8% confidence interval?

12.What is the correct interpretation of the confidence interval from question 11?

13.Are the assumptions met? Explain. Conduct a hypothesis test at the 0.01 significance level to test the researcher’s question.

14.What are the hypotheses?

15.What is the significance level? A. 0.01 B. 0.04 C. 0.05 D. 0.10

16.What is the value of the test statistic?

17.What is the p-value?

18.What is the correct decision? A. Reject the Null Hypothesis B. Fail to Reject the Null Hypothesis C. Accept the Null Hypothesis D. Accept the Alternative Hypothesis

19.What is the appropriate conclusion/interpretation?

20.Are the assumptions met? Explain.

Answer 1

11)

12) We are 99.8% confident that the population mean cholesterol level of the general US male population lie within the interval (190.308,197.692)

13-14)

15) significance level = 0.01

16) Test statistic :

degree of freedom = n-1=81-1=80

17) P value for the two tailed test = 0

18) Since the P value is less than the significance level of the test, we can reject the null hypothesis.

Option A is right.  Reject the Null Hypothesis

19) We have a significant evedence that the average cholesterol for men in the US is different from 189 mg/dL