Bookstore buys a popular freshman physics book at $30 each and sells it to students at $50 each. The same book is used for Fall and Winter terms. The demand for books is distributed Normally with a mean of 150 and 200 for Fall and Winter terms, respectively. The standard deviation of demand is 50, for Fall as well as Winter terms. The demand for each term can be assumed to be independent. The publisher comes up with a new edition every year, making the old edition of the book worthless. The Bookstore simply throws away any leftover books at the end of the academic year (Winter Term). You have been asked to help the Bookstore in its purchasing decision for Physics books.
(a) Suppose the Bookstore used a newsvendor model to order books for each term. How many books should they order for Fall term and for the Winter term?
(b) Bill Nye, the new purchasing guy, at the Bookstore thinks one can just use the total demand for the year and make one purchasing decision for the whole year. How much should he order using this reasoning? Why this order quantity is different than the sum of order quantities computed separately for Fall and Winter in part (a)? (c) What would YOU recommend to the bookstore? Propose an ordering policy (with numbers, if you can) and explain why this is a better alternative. Is your policy the best one can do? Why (not)?