researchers carried out an experiment to evaluate effectiveness of using acupuncture to treat heel pain. in this experiment 84 patients experiencing heel pain were randomly assigned to one of two groups. one group received acupuncture and the other group received sham treatment that consisted of using a blunt needle that did no penetrate the skin. of the 43 patients in the sham treatment group 16 reported pain reduction of more than 13 points on a foot pain scale this was considered a meaningful reduction in pain. of the 41 patients in acupuncture group 28 reported pain reduction of more than 13 points on the foot pain scale.

a. use a 95% confidence interval to estimate the difference in the proportion who experince a meaningful pain reduction for the acupuncture treatment and for the sham treatment. use Pacupuncture - Psham. use table or SALT. round answers to four decimasl places.