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-after" differences. Does hypnotism appear to be effective in reducing pain? Before After 8.8 5.7 6.1 9.5 10.6 9.4 4.3 1.0 6.6 2.5 7.4 8.3 8.7 6.9 3.4 2.5 Construct a 95% confidence interval for the mean of the "before-after" differences. ]