EXAMPLE 4.33

What about credit hours? In the previous exercise, we examined the number of courses taken in the fall and in the spring at a small liberal arts college. Suppose that we were interested in the total number of credit hours earned for the academic year. We assume that for each course taken at this college, three credit hours are earned. Let T be the mean of the distribution of the total number of credit hours earned for the academic year. What is the mean of the distribution of T? To find the answer, we can use Rule 1 with a = 0 and b = 3. Here is the calculation:

The mean of the distribution of the total number of credit hours earned is 25.11.