Question

If the covariance between x and y is 10 and the variance of x and y are 16 and 9 respectively, then the coefficient of correlation between x and y is

• A. 0.61
• B. 0.79
• C. 0.83
• D. 0.93

Answer 1

Answer: (C)

0.83

Answer 2

$C ⥂ ov(x,y) = 10$, $Var(x) = 16$, $Var(y) = 9$

$\therefore$ $r = \frac{C ⥂ ov(x,y)}{\sqrt{Var(x).Var(y)}} = \frac{10}{\sqrt{16 \times 9}} = \frac{10}{12} = 0.83$.