The expected value of X is 1 and is the same as X's SD. The expected value of Ysquare is 3, the expected value of (Y+1)square equals to 4, the expected value of (X+Y)square is 7. I got stuck at figuring out E(Y+1)square. any hint that can help me solve this? thanks
This seems to be a homework problem. However, let me summarize, you have:
You search: $$(E(Y+1))^2 =? $$ Note that $$(Y+1)^2= Y^2+2Y+1.$$ Hence using the linearity of the expectation, i.e. the rule $E(aX+b) = aE(X)+b$, you may derive $E(Y)$ from your given values and finally derive $(E(Y+1))^2$.