A national chain of fastfood restaurants has a 1800 customer service line to deal with customer complaints. The number of calls received in any given hour is thought to follow a Poisson distribution. Over the past year_._ the customer service line has received an average of 25.4 calls per hour. (a) What is the probability that 10 or fewer calls will be received in a given hour? (b) What is the probability that 15 or more calls will be received in a given hour? (c) If any one operator is able to answer 6 calls per hour, how many operators should the customer service line employ in order to be 95% confident that the operators will be able to handle all of the calls received in a given hour? (d) If, in a given hour, the customer service line received 60 calls, what would you conclude