An instructor has given a short quiz consisting of two parts. For a randomly selected student, let X =the number of points earned on the first part and Y =the number of points earned on the second part. Suppose that the joint pdf of X and Y is given in the accompanying table.
y
P(x, y) 0 5 10 15
0 .02 .06 .02 .10
x 5 .04 .15 .20 .10
10 .01 .15 .14 .01
(a) If the score recorded in the grade book is the total number of points earned on the two parts, what is the expected recorded score E(X + Y)? (Enter your answer to one decimal place.) -2.86 x (b) If the maximum of the two scores is recorded, what is the expected recorded score? (Enter your answer to two decimal places.) -0.18
