9. Suppose a bank has one automatic teller machine. Customers arrive at the machine at a rate of 20 per hour and according to a Poisson pattern. (a) What is the probability that no one will arrive in a 15-minute interval? (b) What is the probability that in a 15-minute period, at least 3 people will use the automated teller machines? 10. Suppose the number of flaws in a thin copper wire follows a Poisson distribution with X=2.3 flaws per millimeter. (a) Determine the probability of exactly 2 flaws in 1 millimeter of wire. (b) Determine the probability of 10 flaws in 5 millimeters of wire.