A physical therapist wants to determine the difference in theproportion of men and women who participate in regular sustainedphysical activity. What sample size should be obtained if he wishesthe estimate to be within two percentage points with 99​%​confidence, assuming that
​(a) he uses the estimates of 22.6​% male and 18.9​% female froma previous​ year?
n=____
​(b) he does not use any prior​ estimates?
n=____
