Understanding R Squared Regression for Josh

[JoshMaths]

http://imgur.com/LAOgGyY
http://imgur.com/LAOgGyY

I know the components of R² as in ESS, TSS, RSS.
I know cov(x,y) = [$\sum$(yi - ybar)(xi - xbar)]/n-1

But that's as far as I can go, I have come across lowercase r yet or the sample correlation and proofing how they all fit is a bit beyond me so if someone can provide some help that would be great thanks.

This is not homework.

Josh

 

[mathman]

The link is difficult to read.

 

[JoshMaths]

Sorry about that. Didn't come up in the test so I am all good.