Problem 2: Sally Gordon has just completed her MBA degree and is proud to have earned a promotion to Vice President for Customer Services at the First Bank of Seattle. One of her responsibilities is to manage how tellers provide services to customers, so she is taking a hard look at this area of the bank's operations. Customers needing teller service arrive randomly at a mean rate of 30 per hour. Customers wait in a single line and are served by the next available teller when they reach the front of the line. Each service takes a variable amount of time (assume an exponential distribution), but on average can be completed in 3 minutes. The tellers earn an average wage of $18 per hour. A. If two tellers are used, what will be the average waiting time for a customer before reaching a teller? On average, how many customers will be in the bank, including those currently being served? B. Sally feels that a significant cost is incurred by making a customer wait because of potential lost future business. Sally estimates the cost to be $0.50 for each minute a customer spends in the bank, counting both waiting time and service time. Given this cost, how many tellers should Sally employ