Clinical Trials of Lipitor Lipitor (atorvastatin) is a drug used to control cholesterol. In clinical trials of Lipitor, 94 subjects were treated with Lipitor and 270 subjects were given a placebo. Among those treated with Lipitor, 7 developed infections. Among those given a placebo, 27 developed infections. We want to use a 0.05 significance level to test the claim that the rate of infections was the same for those treated with Lipitor and those given a placebo.

a. Test the claim using a hypothesis test.

b. Test the claim by constructing an appropriate confidence interval.

c. Based on the results, is the rate of infections different for those treated with Lipitor?