Q. The two regression lines are $2x - 7y + 6 = 0$ and $7x - 2y + 1 = 0.$ The correlation coefficient between $x$ and y is
A) $- \frac{2}{3}$
B) $\frac{2}{7}$
C) $\frac{4}{9}$
D) None of these
Explanation
(b)
Let us assume that line of regression y on x is $2x - 7y + 6 = 0\ and\ x\ on\ y\ is\ 7x - 2y + 1 = 0$
$\therefore b_{yx} = \frac{2}{7}\ and\ b_{xy} = \frac{2}{7}$
$\therefore\ \ \ r = \sqrt{\left( \frac{2}{7} \right)\left( \frac{2}{7} \right) =}\frac{2}{7}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.