Regression analysis - Wikipedia
https://en.wikipedia.org/wiki/Regression_analysisIn the more general multiple regression model, there are independent variables: = + + + +, where is the -th observation on the -th independent variable.If the first independent variable takes the value 1 for all , =, then is called the regression intercept.. The least squares parameter estimates are obtained from normal equations. The residual can be written as
Regression toward the mean - Wikipedia
https://en.wikipedia.org/wiki/Regression_toward_the_meanIn statistics, regression toward the mean (also called regression to the mean, reversion to the mean, and reversion to mediocrity) is the phenomenon that arises if a sample point of a random variable is extreme (nearly an outlier), in which case a future point is likely to be closer to the mean or average. To avoid making incorrect inferences, regression toward the mean must be considered when de…