We have m times the mean of the x's, plus b, is equal to the mean of the y's. Now, I actually want to get both of these into mx plus b form. This is actually already there. So you can see that if our line, if our best fitting line is going to be y is equal to mx plus b, we still have to find the m and the b. But we see on that best fitting line, because the m and the b that satisfy both of these equations are going to be the m and the b on that best fitting line. So that best fitting line actually contains the point. It actually contains the point.