Question: The serum cholesterol level among adults (20 years and older) in the United States is known to be normally distributed with a population mean of 200 mg/dl and a standard deviation of 40 mg/dl. An investigator wants to know if the following sample of people from a heart disease risk reduction class have a mean cholesterol level (measured at the time they enrolled into the class) that is different from the known population: (4 points)

a. What is the independent variable? (¼ pt)

b. What is the dependent variable? (¼ pt)

c. What type of data is the dependent variable? (¼ pt)

d. How many samples test should you use (i.e. one, two, or k)? Describe the samples. (¼ pt)

e. Are the samples related? Justify your answer. (¼ pt)

f. What is the most appropriate statistical test to use to determine if there is a difference in mean cholesterol level between the sample of people from the heart disease risk reduction class and the U.S.? Justify your answer. (½ pt)

g. What is the mean cholesterol level for the heart disease risk reduction class? (¼ pt)

h. What is the standard deviation for the heart disease risk reduction class? (¼ pt)

i. What is the value of the observed test statistic? (¼ pt)

j. What is the critical value of the observed test statistic needed to reject the null hypothesis at an alpha level of .05? (¼ pt)

k. Using all the information available on the spreadsheet and in the attached tables, what is the best estimate you can make for p? (¼pt)

l. With an alpha level of .05, would you reject the null that there is no difference between the mean cholesterol level of the heart risk reduction class and the U.S. population? (½ pt)

m. Based on this cholesterol data only, is it appropriate for people in the heart disease risk reduction class to be enrolled in this class? Justify your answer. (½ pt)