53. A store opens at 8 A.M to 5 RM. From 8 until 10 AM. customers arrive at a Poisson rate of PIN/2 an hour. Between 10 AM. and 12 PM. they arrive at a Poisson rate of HM an hour. From 12 RM. to 2 PM. the arrival rate increases to PM + DD per hour; and from 2 to 5 PM. the arrival rate drops to RIM/2 per hour. Determine the probability distribution of the number of customers that enter the store on a given day