Editing Pearson correlation coefficient (section)

==Motivation/Intuition and Derivation==
The correlation coefficient can be derived by considering the cosine of the angle between two points representing the two sets of x and y co-ordinate data.<ref>{{Cite web |title=How was the correlation coefficient formula derived? |url=https://stats.stackexchange.com/questions/635637/how-was-the-correlation-coefficient-formula-derived |access-date=2024-10-26 |website=Cross Validated |language=en}}</ref> This expression is therefore a number between -1 and 1 and is equal to unity when all the points lie on a straight line.