A researcher wished to compare the effect of two stepping heights (low and high) on heart rate in a step-aerobics workout. A collection of fifty adult volunteers was randomly divided into two groups of twenty-five subjects each. Group 1 did a standard step-aerobics workout at the low height. The mean heart rate at the end of the workout for the subjects in Group 1 was x1 = 90.00 beats per minute with a standard deviation s1 = 9 beats per minute. Group 2 did the same workout but at the high step height. The mean heart rate at the end of the workout for he subjects in Group 2 was x2 = 95.08 beats per minute with a standard deviation s2 = 12 beats per minute. Assume that two groups are independent and the data are approximately normal. Let µ1 and µ2 represent the mean heart rates we would observe for the entire population represented by the volunteers, if all members of this population did the workout using the low or high step height, respectively. Suppose the researcher had wished to test the hypotheses H0: µ1 = µ2 and Ha: µ1 < µ2. The P-value for the test is (use conservative value for the degrees of freedom)
A. between 0.01 and 0.05.
B. between 0.05 and 0.10.
C. larger than 0.10.