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 10.7 7.6 9.2 11.5 9.8 4.9 2.2 After 1.7 6.2 2.8 7.3 8.9 8.1 6.2 3.6 2.4 Construct a 95% confidence interval for the mean of the "before - after" differences. - 12.81