A researcher would like to evaluate the effectiveness of a pain-relief patch designed for lower back pain. Prior to testing the patch, each of n = 8 patients rates the current level of back pain on a scale from 1 to 10. After wearing the patch for 90 minutes, a second pain rating is recorded. The data are as follows: Before After 6 2 8 3 9 4 8 1 10 2 5 3 9 8 7 7 Compute the mean and variance for the sample of difference scores. Do the results indicate a signicant difference? Use a two-tailed test with a = .05 Compute Cohen's d to measure the size of the effect. What are the hypotheses for this study? Hypotheses: Ho & H1? ' uD =8, uD not= 8 O uD=0, uD not= O Compute Cohen's d to measure the size of the effect. What is the df for this study? 0 7 15 0 8 O 16\fWhat is the correct decision for this study? ' Accept Ho / Fail to Reject Ho Reject H1 ' Accept H1 Reject Ho