Flaws in aluminum siding. [Note: This exercise refers to an optional section in Chapter 4.] A building contractor has decided to purchase a load of factory-reject aluminum siding as long as the average number of flaws per piece of siding in a sample of size 45 from the factory’s reject pile is 1.5 or less. If it is known that the number of flaws per piece of siding in the factory’s reject pile has a Poisson probability distribution with a mean of 1.75, find the approximate probability that the contractor will not purchase a load of siding. [Hint: If x is a Poisson random variable with mean l, then s2x equals l>n.]