Suppose that Y is a discrete random variable that has uniform distribution on the n numbers {a, a + b, . . . , a + (n 1)b}, and that X is another discrete random variable that has uniform distribution on {1, 2, . . . , n}. Write Y as a linear function of X. Using properties of expectation/variance, find formulae for the expectation and variance of Y in terms of a, b, and n