Question

Suppose a​ least-squares regression line is given by modifyingabove y with caret equals 4.302 x minus 3.293y=4.302x−3.293. what is the mean value of the response variable if x equals 20x=20

Answer 1

We are given the following relation:

y = 4.302 x – 3.293

To solve for the mean value of y when x = 20, what we have to do is to find for the value of y at x = 20 and the value of y at x = 0. Then we get the average of the two values.

when x = 0

y(0) = 4.302 (0) – 3.293

y(0) = - 3.293

 

when x = 20

y(20) = 4.302 (20) – 3.293

y(20) = 82.747

 

The mean value would be:

mean y = [y(20) + y(0)] / [20 + 0]

mean y = [82.747 + (-3.293)] / 20

mean y = 3.9727 = 3.97