Customers arrive at the service shop with one server following a Poisson process, with the mean arrival rate of 6/hour, the service time per each customer is exponential distributed with the mean service time of 8 minutes. Assuming there are enough space for customers to wait,

a. What the probability that the shop has no customer in it?

b. What the probability that there are 4 customers in the shop?

c. What the probability that there are at least one customer in the shop?

d. What is the mean number of customers in the shop? e. What the mean number of customer waiting in the queue?

f. What the mean waiting time in queue?

Textbook: Systems Engineering Design Principles and Models By Dahai Liu