I have two random variables X and Y, and I need to calculate E(XY). The expectation of X, E(X) =(adsbygoogle = window.adsbygoogle || []).push({}); aZ, and the expectation of Y, E(Y) =bZ, whereaandbare known constants and Z is a random variable.

So the question is how would I calculate E(XY)?

I was thinking that I could do the following:

E(XY) = E(aZ,bZ)

=> E(XY) = ab*E(ZZ)

=> E(XY) = ab*E(Z^2)

Is it correct to do this?? or how would I do it?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Expectation of random variable

**Physics Forums | Science Articles, Homework Help, Discussion**