## Residual Analysis

The data set consists of

- Response (dependent variable) for 's;
- 1st predictor (1st explanatory variable) for 's;
- 2nd predictor (2nd explanatory variable) for 's.

The prediction equation provides a fitted value

*standardized residuals*.

In model validation we look for a pattern, the indication of which suggests that the regression of choice is not a good model.