A Researcher Wished to Compare the Effect of the Frequency

Multiple Choice

A researcher wished to compare the effect of the frequency of the rate of stepping on heart rate in a step-aerobics workout. A collection of 30 adult volunteers, 15 women and 15 men, was selected from a local gym. The men were randomly divided into three groups of five 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 rapid rate. The women were also randomly divided into three groups of five subjects each. As with the men, each group did one of the three standard step-aerobics workouts. The mean heart rate at the end of the workout for all subjects was determined (in beats per minute) . A partial ANOVA table for these data is given below. Analysis of variance for heart rate: Since there is little evidence of interaction and the main effect of stepping is significant, we can conclude that:

A) the population mean heart rate for the rapid-rate group is higher than the other two groups.
B) the population mean heart rate for the low-rate group is lower than the other two groups.
C) the population mean heart rate for the low-rate group is lower than that of the medium-rate group.
D) None of the answer options is correct.