Question

For the two regression equations 4y = 9x + 15 and 25x = 6y + 7 find correlation coefficient r, `barx, bary`

Answer 1

Given equations of regression lines are

4y = 9x + 15 and 25x = 6y + 7

y = `9/4x + 15/4` and y = `25/6x - 7/6`

`9/4x + 15/4 and y = 25/6x - 7/6` 

`|9/4| < |25/6|`

b_xy = `9/4. 1/(b_xy) = 25/6`

b_xy = `9/4. b_xy = 6/25`

r = `sqrt(b_xy xx b_yx)`

= `sqrt(6/25 xx 9/4)`

= `sqrt90.54)`

r = ± 0.7348

r = 0.7348     ............(b_xy, b_yx > 0)

Solving equations of regressions lines

`barx = 118/46 . bary = 438/46`