### Identifying Explanatory and Response Variables

- It is important to correctly select the explanatory and response variables when using regression, or the relationship will be incorrect.
- The explanatory variable is the variable which is used to explain or predict the response variable.
- In a conventional x-y dataset, the x variable is the explanatory variable and y is the response variable.

### Fitting Least Squares Models

- Start by identifying the explanatory and response variables.