Problem: EfficientResponse specializes in providing call center services to major electronics retailers. Recently, CheapTronics, a company which had outsourced its call center operations to EfficientResponse brought up its customers' complaints about the long wait times during late hours, which is particularly an issue for the company's "gold" customers who had enrolled in CheapTronics' reward program. EfficientResponse employs only one agent during the late night shift. The number of calls during this time period is random with an average of 30 per hour and CVa=1. Service times are random as well, with CVp=1; each call takes on average 1.5 minutes (not including the wait time).
Question: How long would the customers who call during the late hours wait on average? CheapTronics also suggests that the agents must promote newer products of the company when they respond to calls. This activity has some marketing value, but it doubles the average call time (not including the wait). At a minimum, how many more agents should EfficientResponse utilize during the late hour shift to respond to the calls just sufficient capacity?