# Math Help - Expectation and Variance

1. ## Expectation and Variance

If anyone helps me with two questions attached, I will be thankful.

Selin

2. Originally Posted by selinunan
If anyone helps me with two questions attached, I will be thankful.

Selin
For the first question you are given enough information to write down joint density:

$f_{X,Y}(x,y)=f_{Y|X}(y|x)f_X(x)$

and the rest follows.

CB