Question

Find correlation coefficient $f(x,y)$, where
$cov(x,y)=-2.25$,
$var\left(x\right)=6.25$,
and $var\left(y\right)=20.25$

Answer 1

$cov(x,y)=-2.25$,
$var\left(x\right)=6.25$,
and $var\left(y\right)=20.25$
$\rho (x,y)=$?
$\rho (x,y)=\frac{cov(x,y)}{\sqrt{var\left(x\right)}\sqrt{var\left(y\right)}}=\frac{-2.25}{2.5\times 4.5}$
$=\frac{-9}{45}=-\frac{1}{5}=-0.2$
$\because$ value of $\rho$ is negative
$\therefore$ correlation is negative