The Universities' bookstore stocks textbooks based on departmental predicts and pre-registration records to find out how many copies are required. Pre-registration illustrates 90 students enrolled, but bookstore manager says that based on his intuition and some historical evidence; he thinks that distribution of sales may range from 70 to 90 according to following probability model.
Demand 70 75 80 85 90
Probability .15 .30 .30 .20 .05
Textbook costs bookstore $82 and sells for $112. Any unsold copies can be returned to publisher, less restocking fee and shipping, for net fund of $36.
1- How to create the table of conditional profits?
2- How many copies must bookstore stock to get highest expected value?