A researcher wishes to compare the effect of the rate of stepping on heart rate in a step-aerobics workout. A collection of 30 adult volunteers was randomly divided into three groups of 10 subjects each. Each group did a standard step-aerobics workout with group 1 at a low rate of stepping, group 2 at a medium rate of stepping, and group 3 at a high rate of stepping. The mean heart rate at the end of the workout for all subjects was determined in beats per minute. Assume the data for the three groups are independent and the data are approximately Normal. The means and standard deviations of the heart rates for the three groups are given below.
An ANOVA F test was run on the data with the following results.
Multiple comparison procedures are going to be done using the Bonferroni method with = 0.10. The value of t ** is 2.2426. Which of the following is the appropriate conclusion from carrying out these multiple comparisons?
A. Group 3 has a higher mean heart rate than either group 1 or group 2. Group 1 and group 2 are indistinguishable.
B. Group 3 has a higher mean heart rate than group 1. The other pairs of means are indistinguishable.
C. Neither choice is correct.