# Linear Regression (Sxy) proof help needed

• May 30th 2009, 05:36 PM
StillRussian
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

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