How is it the Hat matrix spans the column space of X? Really nice

Span, Matrix Column Space

Vector spaces induced by matrices: column, row, and null spaces

What is Column Space? — Example, Intuition & Visualization

Example of a projection of a matrix 3 × 2 on the column space

Solved 7. Let A be a 5 x 3 matrix of rank 3. (a) What is the

Describing the Column Spaces (Lines or Planes) of these particular

A quick example calculating the column space and the nullspace of

Least Squared Method and Projection Matrix

Introduction to the Hat matrix in regression

Econometrics

Principles and Techniques of Data Science - 12 Ordinary Least Squares

Row and column spaces - Wikipedia

What is actually a hat matrix? - Quora

Row and column spaces - Wikipedia