A formula for calculating the correlation coefficient r

A formula for calculating the correlation coefficient r

The complete name of the so-called "correlation coefficient" should be "simple linear correlation coefficient", which describes the degree of linear correlation between two variables. Its formula is as shown in the following picture. It does not have the so-called "curve correlation coefficient"!!!!!!!!!!!!!!!!!!! In addition, there is "multiple correlation number", which is the concept of multiple linear regression. It is a variable y and multiple independent variables x1, X2 I'm afraid that's not what you want to ask