With a height of 69 in, ronald was the shortest president of a particular club in the past century. the club presidents of the past century have a mean height of 71.6 in and a standard deviation of 2.4 in. a. what is the positive difference between ronald's height and the mean? b. how many standard deviations is that [the difference found in part (a)]? c. convert ronald's height to a z score. d. if we consider "usual" heights to be those that convert to z scores between minus2 and 2, is ronald's height usual or unusual?