Pfizer would like to test the effectiveness of a new cholesterol medication it has recently developed. To test the effectiveness, the LDL cholesterol level of 12 randomly selected individuals was measured before and after they took the medication. The data are shown as follows and can be found in the Excel file cholesterol.xlsx.

Person Before After Person Before After 1 187 144 7 184 105 2 196 146 8 185 104 3 184 117 9 212 138 4 180 104 10 206 125 5 208 114 11 192 120 6 203 135 12 175 121

a. Using a = 0.01, perform a hypothesis test to determine if the average LDL level is more the 50 points lower for patients who have taken the new medication.

b. Approximate the p-value using Table 5 in Appendix A and interpret the result.

c. Construct a 99% confidence interval to estimate the average difference in LDL levels for people before and after they take the medication.

d. Verify your results using Excel.

e. Identify the p-value using Excel and interpret the result.

f. What assumptions need to be made in order to perform this procedure?

AppendixLO1