3. A bookstore purchases four copies of a book at $5.00 each and sells them for $10.00 each. Unsold copies are returned for $2.00 each. Let X be the number of copies sold, and Y be the net revenue. Thus Y- g(x) - 10X + 2(4- X) - 20. If the probability distribution of X is 0 1 2 3 4 p(x) .08 34 13 23 .22 (a) (2 pts) What is the probability that the bookstore makes money (i.c. they have positive revenue)? (b) (S pts) find the expected value of Y