Take tab #1of the Barber Shop simulation example (under “Excel Examples”) and modify it as follows. Change the distribution of service times to normal, with a mean of 20 minutes and a standard deviation that you will choose. To facilitate comparisons, you will need to change both the inter-arrival and service time calculations so th at they are based on “dead” sets of 0-1 random numbers (different sets for each item!). Now explore the effects of changing the standard deviation from 0 up to 5 minutes. Specifically, look at the effect on time spent waiting in line (Wq). You won’t be able to simulate a zero standard deviation with the formula, but you can easily insert constant service times manually to get this value. Plot the results to show the effect.