- #1
laz0r
- 17
- 0
Homework Statement
Prove that
[tex]\sum[(x_{i} - \overline{x})(y_{i} - \overline{y})] = \sum[(x_{i} - \overline{x})y_{i}][/tex]
Homework Equations
None.
The Attempt at a Solution
I tried using the fact that the sum of the mean values is just the mean value, because the sum of a constant is simply a constant, and I expanded out the first sum, but I didn't end up anywhere.
[tex] \sum[x_{i}y_{i}] - \overline{y}\sum(x_{i}) - \overline{x}\sum(y_{i}) + \overline(x)\overline(y) [/tex]
I have no idea where to go from here, so some inspiration would be much appreciated.