Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study, researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (average age 58). After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the inactive pill.

a) State the appropriate hypotheses.

b) Obtain a test statistic and p-value. Interpret the results at ? = .01.

c) Is normality assured?

d) Is the difference large enough to be important?

e) What else would researchers need to know before prescribing this drug widely?