Model the queuing system in Excel. You can set the parameters yourself. After you do your modeling, write a small evaluation article about it.

The main thing in the question is not the solution of the problem, but the correct modeling in EXCEL !!!

An average of 50 customers per hour arrive at a small post office. Interarrival times are exponentially distributed. Each window can serve an average of 25 customers per hour. Service times are exponentially distributed. It costs $25 per hour to open a window, and the post office values the time a customer spends waiting in line at $15 per customer-hour. To minimize expected hourly costs, how many postal windows should be opened? ( Model the queuing system in Excel!!!! You can set the parameters yourself.)