You’re working at Boeing after graduation and they have a self serve coffee urn in their employee lunchroom. Arrivals at the urn follow a Poison distribution at the rate of three per minute. In serving themselves, customer take, on average, 15 seconds, exponentially distributed.
a. How many customers would you expect to see, on average, at the coffee urn?
b. How long will customers wait in line and to be served”
c. What percentage of the time is the urn in use?
d. What is the probability that three people will be at the urn?