Aspirin, a longtime antidote for the side effects of drinking alcohol, may actually enhance alcohol's effect. In a report published in the Journal of the American Medical Association, researchers found that aspirin lowered the body's ability to break down alcohol in the stomach. Volunteers were used to test the effect of aspirin on alcohol. Each of the 35 volunteers came to the research center twice. Once they ate a standard breakfast and drank 2 glasses of wine. Another time they ate a standard breakfast, drank 2 glasses of wine and took 2 extra-strength aspirin tablets. The mean difference (with aspirin - without aspirin) in their blood alcohol levels was 0.02 with a standard deviation of 0.04. The researchers want to determine if aspirin causes an increase in the mean difference in blood alcohol levels for volunteers like these.

(a) What additional information would you need to confirm that the conditions for this test have been met?

(b) Assume the conditions have been met. Calculate the standardized test statistic and P-value for this test.

(c) Interpret the P-value and draw the appropriate conclusion at the = 0.05 significance level.

(d) Given your conclusion in part (c), which type of error, type I or type II, could you have made? Describe that error in the context of this study.