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 73.7 in and a standard deviation of 2.6 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?