# Thread: Linear Regression (Sxy) proof help needed

1. ## Linear Regression (Sxy) proof help needed

Hello everyone!

I am looking for help with proving the following:

Sum(xi - x_bar)(yi - y_bar) = Sum(xi- x_bar)yi

Thanks in advance!

2. Going through the sum, this boils down to showing that $\Sigma (x_i - \bar{x}) = 0$

3. Aaaaahhhrrgh

Thank you so much! I cannot believe I did not see this! Thank you again!