Two components of a minicomputer have the following joint pd

Two components of a minicomputer have the following joint pdf for their useful lifetimes X and Y:

a. What is the probability that the lifetime X of the first component exceeds 3?

b. What are the marginal pdf\'s of X and Y? Are the two lifetimes independent? Explain.

**** I need help with this: Reconsider the minicomputer component lifetimes X and Y
as described in Exercise 12. Determine E(XY). What can besaid about Cov(X, Y) and r?

Solution