4. The average number of shipments that arrive at a landing area within a depot is three per hour during a regular business day. The process can be modeled with the Poisson distribution. These shipments arrive randomly and are not related to each other in any way. a. What is the probability that more than two will arrive in a one-hour period ? b. What is the chance that an hour goes by, and no shipments arrive ? c. What is the probability that 2 hours go by and no more than two shipments arrive at the platform