38. A chemical supply company currently has in stock 100 lb of a certain chemical, which it sells to customers in 5-lb containers. Let X  the number of containers ordered by a randomly chosen customer, and suppose that X has pmf Compute E(X) and V(X). Then compute the expected number of pounds left after the next customer s order is shipped and the variance of the number of pounds left. (Hint: The number of pounds left is a linear function of X.)