35.1 Introduction

In the last chapter, correlation was studied, which measures the strength of the linear relationship between two quantitative variables \(x\) and \(y\). We now study regression, which describes what the linear relationship is between \(x\) and \(y\).

The relationship is described using an equation, which allows us to:

1. Predict values of \(y\) from given values of \(x\) (Sect. 35.4); and
2. Understand the relationship between \(x\) and \(y\) (Sect. 35.5).