4. A local sandwich shop, running under Covid-19 restrictions, can have at most 2 customers inside at any one time. Customers arrive according to a Poisson process with a rate of 3 per minute. Service times are iid and exponential with a mean of 2 minutes per order. If a customer arrives when there are already 2 customers inside, they leave because it is cold and rainy outside and there are many more places to eat nearby. (a) What is the average number of customers in the shop in equilibrium? (b) If the shop employees could work twice as fast, how much more business would they do? 4. A local sandwich shop, running under Covid-19 restrictions, can have at most 2 customers inside at any one time. Customers arrive according to a Poisson process with a rate of 3 per minute. Service times are iid and exponential with a mean of 2 minutes per order. If a customer arrives when there are already 2 customers inside, they leave because it is cold and rainy outside and there are many more places to eat nearby. (a) What is the average number of customers in the shop in equilibrium? (b) If the shop employees could work twice as fast, how much more business would they do