Why n − 2 in Regression Variance?
Starting from n − 1 in sample variance, use the intuition of a fitted line chasing the data to see why regression uses n − 2.
Sep 22, 2026
Optional Extension · How Do We Fit a Curve?
From nearest neighbours to kernel and local linear regression: local weighting, Taylor expansion, weighted least squares, and Python implementations.
Sep 20, 2026
Tutorial 4 Extension · What Is Leverage and Why It Matters?
An intuitive introduction to leverage, hat values, and standardized residuals in linear regression.
Sep 12, 2026