Given the joint density function [begin{aligned} f(x, y) & =frac{1}{left(x_{2}-x_{1} ight)left(y_{2}-y_{1} ight)} 2 & leq x leq 4, text { and } 1 leq

Given the joint density function

\[\begin{aligned} f(x, y) & =\frac{1}{\left(x_{2}-x_{1}\right)\left(y_{2}-y_{1}\right)} \\ 2 & \leq x \leq 4, \text { and } 1 \leq y \leq 3 \end{aligned}\]

evaluate \(E\{X\}, E\{X Y\}, \operatorname{Cov}(X Y)\), and \(ho\). Note that \(f(x, y)=f(x) f(y)\).