A large shopping mall is considering opening an information desk that one employee will staff. An average of one customer is thought to come to the desk every three minutes. The employee can take care of thirty customers per hour on average. The information desk employee earns $5/hour, and the cost of waiting time, in terms of customer unhappiness with the mall, is $12/hour spent waiting in line. Assuming that arrivals are Poisson distributed and answer times are exponentially distributed, what are the total expected costs over an 8-hour day? $136 $128 $96 $278 $310