Below are normal probability plots of the HBE data from Exercise 7.10.8.
(a) Using the plots to support your answer, is there evidence of abnormality in either of the samples?
(b) Considering your answer to (a) and the preceding plots, should we conclude that the data are indeed normally distributed? Explain.
(c) If the data are indeed normally distributed, explain in the context of this problem what the drawback would be with using the Wilcoxon-Mann-Whitney test over the two-sample t test to analyze these data.
(d) If the data are not normally distributed, explain in the context of this problem what the drawback would be with using the two-sample t test over the Wilcoxon-Mann-Whitney test to analyze this data.
(e) Considering your answers to the above, argue which test should be used with these data. Note there is more than one correct answer.

Joggers 60 50- 40- 30- 20- Normal score Fitness program 70 60- E 40 20- 10 -2 1 0 Normal score