A bank has one drive-up teller. The teller can serve at the rate of 10.5 bank customers in an hour. Customers arrive at the drive-up window on an average every 7.5 minutes. The bank is currently analyzing the possibility of adding a second drive-up window at an annual cost of $18,000. It is assumed that arriving cars would be equally divided between both windows. It is estimated that each minute’s reduction in customer waiting time would increase the bank’s revenue by $2,400 annually. What will be net change in the bank’s revenue? Should the second drive-up window be installed?
Note: Do hand calculations to answer this question. Show all details of your answer.