Question

The random variables X and Y are independent if ______ 

(a) E(XY) = 1 

(b) E(XY) = 0 

(c) E(XY) = E(X) E(Y) 

(d) E(X + Y) = E(X) + E(Y)

Answer 1

(c) E(XY) = E(X) E(Y)