Two pencils are selected at random from a box containing 2 red, 3 blue and 2 yellow pencils. Let R=the number of red pencils among the two chosen and B-the number of blue pencils among the two chosen. The resulting joint probability distribution, p(r,b) of R and B is p(r,b) 0 0 1 B 2 3/28 9/28 3/28 R 1 6/28 6/28 0 2 1/28 0 0 a. Find the marginal distribution of B. b. Are R and B independent random variables? Support your answer. c. Calculate E(RB). (i.e., the expected value of R times B)