The city of Vancouver Office of Emergency Management reported that 911 operators receive an average of 7.2 calls per hour. Assume that the number of 911 calls follows Poisson distribution
a) What is the probability that exactly five 911 calls will be made during the next hour?
b) What is the probability that three or four 911 calls will be made during the next hour?
c) What is the probability that three or more 911 calls will be made during the next hour?
d) What is the probability that exactly four 911 calls will be made during the next 30 minutes?