5.55 Number of aphids. The milkweed aphid is a common pest to many ornamental plants. Suppose that the number of aphids on a shoot of a Mexican butterfly weed follows a Poisson distribution with μ = 4.4 aphids.
(a) What is the probability of observing exactly five aphids on a shoot?
(b) What is the probability of observing five or fewer aphids on a shoot?