Researchers studied the effects of adding an exercise program to dieting in the
ID: 3367309 • Letter: R
Question
Researchers studied the effects of adding an exercise program to dieting in the achievement of weight loss. A sample of 75 men ages 18-20 (Group 1) were observed for weight loss using a diet only, and another independent sample of 66 men ages 18-20 (Group 2) were put on the same diet, but with an added exercise program. The mean weight loss for Group 1 was 7.5 pounds with a standard deviation of 4.8 pounds, and the mean weight loss for Group 2 was 14.8 pounds, with a standard deviation of 6.1 pounds.
Calculate the upper bound of a 99% confidence interval for the difference in mean weight loss for the two groups to two decimal places. Assume the population standard deviations are NOT equal
Explanation / Answer
The statistical software output for this problem is:
Two sample T summary confidence interval:
?1 : Mean of Population 1
?2 : Mean of Population 2
?1 - ?2 : Difference between two means
(without pooled variances)
99% confidence interval results:
Hence,
Upper bound of 99% confidence interval = -4.86
Difference Sample Diff. Std. Err. DF L. Limit U. Limit ?1 - ?2 -7.3 0.93326731 123.04473 -9.741779 -4.858221Related Questions
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