# Thread: The eq of 2 regression lines are

1. ## The eq of 2 regression lines are

The equations of 2 regression lines are
8x - 10y + 66 = 0 , 40x - 18y - 214 = 0

Obtain the standard deviation of Y is standard deviation of X is 3

2. Your 2 equations $8x - 10y + 66 = 0 , 40x - 18y - 214 = 0$ need to be put in the form $y=a+bx$ as this form helps us identify parameters like the standard deviation and the mean.

Note that for $y=a+bx$

$b = r\times \frac{s_y}{s_x}$

$a = \bar{y} -b\bar{x}$

so do you have any additional information?