Answer to Question #10005 in Statistics and Probability for Raghav Agrawal
A publisher sends advertising materials for an accounting text to 80% of all professors teaching the appropriate accounting course. Thirty percent of the professors who received this material adopted the book, as did 10% of the professors who did not receive the material. What is the probability that a professor who adopts the book has received the advertising material?
Total amount of professors who adopted the book (as % of all professros): 80%*30%+10%*20%=26% Amount of professors who receaved and adopted: 80%*30%=24%. The probability of an adopter being a receaver is 24%/26%=92.3%