I'm really confused between correlation, covariance and coefficient (too many C words - and I think think of one more to describe my statistics lecturer with, just kidding)
I understand that covariance is expressed in terms of units whereas correlation is a more standardised measure but I was wondering if that could be proved mathematically as I don't understand the logic behind it.
Also I don't understand why squaring the correlation coefficient is useful aside from getting rid of +/- signs.
Please help! Thank you. Also I didn't do a-level maths or statistics, just a very confused psychology student haha.
What should I do?