Question

Given the following summary statistics, using excel determine the regression equation used to predict y from x . sy = 4.44, sx = 2.36, r = -0.21, ¯ x = 25.42, ¯ y = 79.87 Round all answers to 2 decimal places.

Answer 1

Suppose we have the regression equation y = mx + c

We know that the formula for slope(m) is given as

m =

setting the value of r = -0.21, sy = 4.44 and sx = 2.36

we get, slope(m) =

So, slope m = -0.40

Now, we have to find the value of intercept c

setting the given value of m=-0.40, y(bar) = 79.87, x(bar) = 25.42

we get,

So, regression equation becomes y = 90.04 - 0.40x