In: Statistics and Probability
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 pmf of X and Y is given in the accompanying table.
y | |||||
p(x, y) |
0 | 5 | 10 | 15 | |
x | 0 | 0.03 | 0.06 | 0.02 | 0.10 |
5 | 0.04 | 0.13 | 0.20 | 0.10 | |
10 | 0.01 | 0.15 | 0.15 | 0.01 |
(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.)
(b) If the maximum of the two scores is recorded, what is the
expected recorded score? (Enter your answer to two decimal
places.)