# The two lines of regression are $x+2y-5=0$ and $x+3y-8=0$. The coefficient of correlation between $x$ and $y$ is

$\begin {array} {1 1} (A)\;-0.82 & \quad (B)\;0.82 \\ (C)\;-0.72 & \quad (D)\;0.76 \end {array}$

$x=-2y+5$
$\Rightarrow r_1 = -2$
$y = -\large\frac{1}{3}x+\large\frac{8}{3}$
$r_2= -\large\frac{1}{3}$
$r^2=r_1 \times r_2$
$r^2 = -2 \times -\large\frac{1}{3}$
$= \large\frac{2}{3}$
$r = -0.82$
Ans : (A)
square of r has value 2/3 then r will have values -0.82 and +0.82. How have we choosen -0.82. please clearify it