To see if fish oil can help reduce blood pressure, males with high blood pressure were recruited and randomly assigned to different treatments. Seven of the men were randomly assigned to a 4-week diet that included fish oil. Seven other men were assigned to a 4-week diet that included a mixture of oils that approximated the types of fat in a typical diet. At the end of the 4 weeks, each volunteer's blood pressure was measured again and the reduction in diastolic blood pressure was recorded. The average reduction for the fish oil group was 6.57 and the average reduction for the regular oil group was -1.14. The p-value for the appropriate test is 0.007.

a. Which test should be used to analyze these data?

(a) Paired t test for a mean difference

(b) Two-sample z test for a difference in proportions

(c) Two-sample t test for a difference in means

(d) One-sample z test for a proportion

(e) None of these

b. Assuming alpha = 0.05, which of the following best describes the error the researchers could have made?

(a) Type I: Finding convincing evidence that the fish oil works better, when it really doesn't

(b) Type II: Finding convincing evidence that the fish oil works better, when it really doesn't

(c) Type I: Not finding convincing evidence that the fish oil works better, when it really doesn't

(d) Typer II: Not finding convincing evidence that the fish oil works better, when it really does

(e) Type I: Finding convincing evidence that the fish oil works better, when it really does