# Can I do expectation like this

by aegea
Tags: expectation
 P: 4 You can do it the way you suggested (it is logically correct), but I believe it will make more work for yourself (but I didn't look at it because there is a cleaner way). Here are a few hints that should help: Remember that the expected value function is a linear operator so $$E(Y)=E(160X^2)=160E(X^2)$$ and $$V(X)=E(X^2)-[E(X)]^2$$