Question

A set of X and Y scores has a regression equation with a slope of b = 4. If the mean for the X values is MX = 2 and the mean for the Y values is MY = 6, what is the Y-intercept value for the regression equation?

Answer 1

The Y-intercept value for the regression equation is -2

Explanation:

The linear regression has the form: y = a + b*x, where a is the Y-intercept and b is the slope. To find the a compute the following:

a = MY - b*MX

where MX and MY denotes mean for the X and the Y respectively. Replacing:

a = 6 - 4*2 = -2