Did you notice that the observations used have decreased in the regression model? Earlier in the univariate procedure, we had 594 rows of data, and they have now reduced to 564. We have called the new data the build data. The last 30 observations in the data have been left out of the model-building process, and have been put in a dataset called validation.
We will use the validation dataset later in the chapter:
In the analysis of variance (ANOVA) table, the eight degrees of freedom refer to the eight independent variables that are available to estimate the parameters ...