nurse dren was very interested in the effects of a mind/body program to help manage pain symptoms in individuals with metastatic cancer. she conducted a randomized control trial where data from 30 control group and 30 treatment group participants were collected at baseline and at three months post-intervention. the dependent variable was the patient's self-rated pain rating on an analogue scale ranging from 0 (no pain) to 10 (worst possible pain). assuming that the assumptions were met, which test would you run to examine the difference between the groups as a way to determine treatment efficacy?