Consider regression equation of x on y:
10x – 2y = 4; 10x = 2y + 4
Regression equation of y on x : 2y – 5x = 8 2y = 5x + 8
Solving the two regression equations
10x – 2y = 4
2y – 5x = 8
i.e. 10x – 2y = 4
2y – 5x = 8
i.e. 10x – 2y = 4
(+) -5x + 2y = 8
5x = 12,x = 12/5⇒ x̄ = 2.4
put x̄ = 2.4 in 2y – 5x = 8
2y – 5(2.4) = 8
2y = 8 +12.0
y = 20/2 = 10 ⇒ ȳ = 10.