One indicator of physical fitness is a resting pulse rate. Ten men volunteered to test an exercise device advertised on television by using it three times a week for 20 minutes and ten other similar men did not exercise. Their resting pulse rates (beats per minute) were measured after 6 weeks. Results are summarized below. Researchers want to know if there is evidence that exercise can reduce resting pulse rates.
exercise group mean = 82.40
non-exercise group mean = 85.20
standard error for the difference in the two sample means = 6
1. With the difference in population means defined as "exercise mean minus non-exercise mean" which of the following presents the correct test statistic?
O (82.4 - 85.2) / 6
O (85.2 - 82.4) / 6
O (82.4 - 85.2) / √ (6)
O (85.2 - 82.4) / √ (6)