With a height of 64 in, Marvin was the shortest president of a particular club in the past century. The club presidents of the past century have a mean height of 74.2 in and a standard deviation of 2.4 in. a. What is the positive difference between Marvin's height and the mean? b. How many standard deviations is that [the difference found in part (a)]? c. Convert Marvin's height to a z score. d. If we consider "usual" heights to be those that convert to z scores between - 2 and 2, is Marvin's height usual or unusual? a. The positive difference between Marvin's height and the mean is in b. The difference is standard deviations (Type an integer or decimal rounded to two decimal places as needed.) c. The z score is (Type an integer or decimal rounded to two decimal places as needed.) d. Is Marvin's height usual or unusual? Unusual Usual