You are the buyer for your university bookstore. One of the textbooks has a cost to you of $100 and you sell it to students for $140. Any copies of the book that you order and do not sell to students can be returned to the publisher for an average $80.credit. (Sometimes you can get full credit but sometimes a new edition is published so you get no credit). In one particular course, demand has averaged 400 books each semester, with a standard deviation of 40. What is your Target Service Level? What is your target order quantity for the course?