Samples of a cast aluminum part are classified on the basis of surface finish (in microinches) and edge finish. The results of 100 parts are summarized as follows: edge finish excellent good surface finish excellent good 80 2 10 8

(a) Let 4 denote the event that a sample has excellent surface finish, and let B denote the event that a sample has excel- lent edge finish. Determine the mamber of samples in AB. B, and AUR

(b) Assume that each of two samples is to be classified on the basis of surface finish, either excellent or good, and on the basis of edge finish, either excellent or good. Use a tree diagram to represent the possible outcomes of this experiment.