Question

A study was conducted to measure the effectiveness of hypnotism in reducing pain. The measurements are centimeters on a pain scale before and after hypnosis. Assume that the paired sample data are simple random samples and that the differences have a distribution that is approximately normal. Construct a​ 95% confidence interval for the mean of the ​"before minus−​after" differences.

Does hypnotism appear to be effective in reducing​ pain?

Before 5.6, 2.5, 10.0, 7.9, 7.9, 6.8, 3.2, 6.5

After 6.5, 2.8, 7.3, 8.3, 8.1, 6.5, 3.3, 2.4

Answer 1

Number	Before	After	Difference
	5.6	6.5	-0.9	2.4025
	2.5	2.8	-0.3	0.9025
	10	7.3	2.7	4.2025
	7.9	8.3	-0.4	1.1025
	7.9	8.1	-0.2	0.7225
	6.8	6.5	0.3	0.1225
	3.2	3.3	-0.1	0.5625
	6.5	2.4	4.1	11.9025
Total	50.4	45.2	5.2	21.92

Confidence Interval :-



Lower Limit =
Lower Limit = -0.8298
Upper Limit =
Upper Limit = 2.1298
95% Confidence interval is ( -0.8298 , 2.1298 )