Random Variable Linear Dependence

The rate at which one variable affects another.

• When Covariance $Cov(X,Y)>0$, then on average $X\uparrow$ as $Y\uparrow$ and vice-versa
• When Covariance $Cov(X,Y)<0$, then on average $X\downarrow$ as $Y\downarrow$ and vice-versa