A researcher wants to determine the effect that smoking has on resting heart rate. She randomly selects seven individuals from three categories: (1) nonsmokers, (2) light smokers (fewer than 10 cigarettes per day), and (3) heavy smokers (10 or more cigarettes per day) and obtains the following heart rate data (beats per minute):

(a) Test the null hypothesis that the mean resting heart rate for each category is the same at the a = 0.05 level of significance.
(b) If the null hypothesis is rejected in part (a), use Tukey's test to determine which pairwise means differ using a familywise error rate of a = 0.05.
(c) Draw boxplots of the three treatment levels to support the results obtained in parts (a) and (b).