6.1 Opening Remarks

The PMA6 textbook (Chapter 7) goes into great detail on this topic, since regression is typically the basis for all advanced models.

The book also distinguishes between a “fixed-x” case, where the values of the explanatory variable \(x\) only take on pre-specified values, and a “variable-x” case, where the values of \(x\) are observations from a population distribution of X’s.

This latter case is what we will be concerning ourselves with.