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Linear regression and correlation
Even when there might be a rough linear relationship between two variables, the data in the real-world is never as clean as you want it to be. This tutorial helps you think about how you can best fit a line to the relationship between two variables.
Understanding why correlation does not imply causality (even though many in the press and some researchers often imply otherwise)
Given a random assortment of points, find the best fit line for them.
Introduction to the idea that one can find a line that minimizes the squared distances to the points
Proof (Part 1) Minimizing Squared Error to Regression Line
Proof Part 2 Minimizing Squared Error to Line
Proof (Part 3) Minimizing Squared Error to Regression Line
Proof (Part 4) Minimizing Squared Error to Regression Line
Regression Line Example
Second Regression Example
R-Squared or Coefficient of Determination
Calculating R-Squared to see how well a regression line fits data
Covariance, Variance and the Slope of the Regression Line