Problem 3 Queuing [2 points]

Customers are waiting in one line in front of the Genius Bar at the Apple store. Currently, there are two technicians at the bar helping customers. It takes a technician an average of 15 minutes to solve a problem, while customers arrive at the bar at a rate of 3 customers per hour.

1. [1 point] What queuing model should be used here? What is the hourly arrival rate l? What is the hourly service rate m? How many servers are there?

Model:

l =

m =

S =

For the following questions, round your final answer to 3 decimal places.

2. [0.5 point] What is the average expected number of customers in the Genius Bar system?

3. [0.5 point] On average, how long (in minutes) will it take a customer to get their device fixed, including the waiting time in line?