To calculate the total hourly cost of waiting and cost of providing service if the number of servers, c is 3, we need to consider two main factors: the cost of waiting and the cost of providing service. Cost of Waiting: The cost of waiting is calculated by multiplying the average cost of waiting per minute ($4) by the number of minutes in an hour (60) and then by the average number of callers waiting in line. The average number of callers waiting in line can be calculated using the Performance.xls tool, which takes into account the arrival rate, processing rate, and number of servers. Cost of Providing Service: The cost of providing service is calculated by multiplying the hourly wage of each CSR ($25) by the number of servers (3 in this case). The total hourly cost is then calculated by adding the cost of waiting and the cost of providing service. The negative value of -$79.5 suggests that the company is saving money by having 3 servers, as the cost of providing service is less than the cost of waiting. This is likely due to the reduction in the number of callers waiting in line, which decreases the