Response to the following problem:
Bank Drug Store has two servers. One can serve a customer according to an exponential distribution with a mean speed of 1.5 minutes, and the other can serve a customer according to an exponential distribution with a mean speed of 2 minutes. Customers arrive according to a Poisson process at a mean rate of 60 per hour. Develop an Excel simulation and determine the average time a customer spends waiting in line.
Assume the simulation begins recording the waiting time of the 101 st customer and runs for 1000 customers'.