Atlantic Video, a small video rental store in Philadelphia, is open 24 hours a day, anddue to its proximity to a major business schoolexperiences customers arriving around the clock. A recent analysis done by the store manager indicates that there are 10 customers arriving every hour, with a standard deviation of interarrival times of 2 minute(s). This arrival pattern is consistent and is independent of the time of day. The checkout is currently operated by one employee, who needs on average 2.10 minute(s) to check out a customer. The standard deviation of this checkout time is 3 minute(s), primarily as a result of customers taking home different numbers of videos.

(a) If you assume that every customer rents at least one video (i.e., has to go to the checkout), what is the average time a customer has to wait in line before getting served by the checkout employee, not including the actual checkout time (within one minute)? (Do not round intermediate calculations. Round your answer to two decimal places.)

(b) If there are no customers requiring checkout, the employee is sorting returned videos, of which there are always plenty waiting to be sorted. How many videos can the employee sort over an eight hour shift (assume no breaks) if it takes exactly 1.8 minutes to sort a single video? (Round your answer to nearest whole number.)

(c) What is the average number of customers at the checkout desk (both waiting and being served)? (Do not round intermediate calculations. Round your answer to two decimal places.)

(d) Now assume for this question only that 11 percent of the customers do not rent a video at all and therefore do not have to go through checkout. What is the average time a customer has to wait in line before getting served by the checkout employee, not including the actual checkout time? Assume that the coefficient of variation for the arrival process remains the same as before. (Do not round intermediate calculations. Round your answer to two decimal places.)

(e) As a special service, the store offers free popcorn and sodas for customers waiting in line at the checkout desk. (Note: The person currently being served is too busy with paying to eat or drink). The store owner estimates that every minute of customer waiting time costs the store 8 cents because of the consumed food. Suppose it is possible to add a second employee (server) at the same hourly wage rate as the first employee, $10 per hour. From a total cost perspective, should the second employee be added?

No

Yes