22.31 Side effects. An experiment on the side effects of pain relievers assigned arthritis patients to one of several over-the-counter pain medications. Of the 420 patients who took one brand of pain reliever, 21 suffered some “adverse symptom.’’

  1. (a) If 10% of all patients suffer adverse symptoms, what would be the sampling distribution of the proportion with adverse symptoms in a sample of 420 patients?

  2. (b) Does the experiment provide strong evidence that fewer than 10% of patients who take this medication have adverse symptoms?