18. Heart Rate and Exercise How does exercise affect your heart rate? Ten male subjects were randomly selected from four age groups:

10–19, 20–39, 40–59, and 60–69. Each subject walked on a treadmill at a fixed grade for a period of 12 minutes, and the increase in heart rate, the difference before and after exercise, was recorded (in beats per minute):

Use an appropriate computer program to answer these questions:

a. Do the data provide sufficient evidence to indicate a difference in mean increase in heart rate among the four age groups? Test by using a 5.05.

b. Use Tukey’s pairwise comparison procedure to investigate the differences in increased heart rate among the four age groups. Do your results confirm the results of part a?

10-19 20-39 40-59 60-69 29 24 37 28 33 27 25 22 29 26 33 22 34 27 31 33 36 39 21 28 21 35 28 26 20 33 24 30 25 29 34 34 24 36 21 27 33 22 32 33 32 Total 309 275 295 282