Discuss the following:
Q: Does lovastatin reduce the risk of heart attack? Researchers gave lovastatin to 2,325 people and an placebo to 2,081 people. the average age of both groups in 58 years. After 5 years, 57 of the lavastatin group had suffered a heart attack, compared to 97 from the placebo group. At a=.01, can we conclude that the lovastatin users had a lower incidence of heart attack?
The hypothiese in this problem can be setup for either a left or right tail test, depending on which population you place on the left and right.
Zc=2.326 or -2.325
Z=3.987
normality justified
State the null and alternative hypothesis.
Select a level of significance.
Identify the test statistic.
Formulate a decision rule.
Make a decision.
Is normality assured? Why or why not?
What else would the researcher need to know before prescribing this drug widely?