Janson's Department Store in Stark, Ohio, maintains a successful catalog sales department in which a clerk takes orders by telephone.

Janson's Department Store in​ Stark, Ohio, maintains a successful catalog sales department in which a clerk takes orders by telephone. If the clerk is occupied on one​ line, incoming phone calls to the catalog department are answered automatically by a recording machine and asked to wait. As soon as the clerk is​ free, the party who has waited the longest is transferred and serviced first. Calls come in at a rate of about 11per hour. The clerk can take an order in an average of 4.0minutes. Calls tend to follow a Poisson​ distribution, and service times tend to be negative exponential.

The cost of the clerk is $10 per​ hour, but because of lost goodwill and​ sales, Janson's loses about

$25 per hour of customer time spent waiting for the clerk to take an order.

​a) The average time that catalog customers must wait before their calls are transferred to the order clerk​ =  minutes ​(round your response to two decimal​ places).

​

b) The average number of callers waiting to place an order​ = callers ​(round your response to two decimal​ places).

The present total cost per hour​ (service costplus+waiting cost) = $per hour ​(round your response to two decimal​ places).

​

c) Janson's is considering adding a second clerk to take calls. The store's cost would be the same $8

per hour. The total cost​ (service costplus+waiting cost) = $per hour ​(round your response to two decimal​ places).

By hiring the second​ clerk, the total cost savings per hour for​ Janson's = $

per hour ​(round your response to two decimal​ places).