Problem:

Semester start-ups operations are heavy during the beginning of the semester. Last semester, in the 12 hr 9AM to 9PM workdays of those two weeks, the library 21,600 customers, though, not all were serves all that well.

A study done this past fall shows that:

10% of the early trimester customers to buy one book,
20% percent to buy two,
25% to buy three
30% to buy four
15% to buy five books.

Customers who come in ask for help at the information desk, but the shelf areas for the many schools, departments and courses are clearly marked, so most customers help themselves. Then they come to the cash registers to check out.

The checkout counter had four electronic cash registers.

The cashier's task included:

Keying into the register an inventory code number and a price for each book (Time required: 0.1minutes per book)
Bagging books and receiving payment either by:
collecting cash and making change (Time: 0.4 min per customer)
waiting while the customer wrote a check, then taking down the customer's identification data (Time: 1.2 min per customer)
running a credit card through the register's automatic approval device, filling out a charge slip while waiting for an approval code, getting the customer's signature, and returning the card (Time: 1.0 min per customer).

The store records indicated that:

40% of textbook customers paid cash,
40% paid by check
20% by credit card.

Demand during the first two weeks was fairly level, except during the first two days. It is estimated that the first two days were by far the busiest, with their total volume per day double the average daily volume of the twelve-day period. The busiest hours on those peak days were between noon and 4:00PM, when students came to buy books just after attending their first classes. The bookstore manager said that

Required:

Question 1) What is the capacity of the bookstore checkout stations in customers per hour?

Question 2) What is the average hourly demand during the peak periods of the first two weeks of the semester?

Question 3) What should the manager at the bookstore do?