Question

If the regression equations of the variables x and y be x = 19.13 – 0.83y and y = 11.64 – 0.50x, then the correlation coefficient between x and y is

• A. 0.66
• B. – 0.64
• C. 0.001
• D. – 0.001

Answer 1

Answer: (B)

– 0.64

Answer 2

The given lines of regression are

$x = - 0.83y + 19.13$ and $y = - 0.50x + 11.64$

$\Rightarrow$ $r = - \sqrt{0.83 \times 0.50} = - 0.64$,

(Because both gradients are negative).