Question

The standard deviation for variables x and y be 3 and 4 respectively and their covariance is 8. then coefficient of correlation between them is

• A. $\frac{2}{3}$
• B. $\frac{3}{2\sqrt{2}}$
• C. $\frac{2\sqrt{2}}{3}$
• D. $\frac{2}{9}$

Answer 1

The correct option is A $\frac{2}{3}$

Using fact coefficient of correlation $r_{xy}=\frac{Cov\left(xy\right)}{{\sigma }_x{\sigma }_y}=\frac{8}{3\times 4}=\frac{2}{3}$