Projecting values from predictor variables
As we saw in the previous section, the first task when building a predictor model is to test whether the predictor variables have a close relationship with the result variable. In this section, we will learn the introductory concepts of statistical tests for relationships between variables. Linear model accuracy is represented by the concepts displayed in Figure 2.6:
The visual elements of the statistical methods to measure the variables' relationships are as follows:
- The sales average is the horizontal line near 15 on the y axis.
- The linear model is shown by the diagonal line. This line predicts the future values.
- Unexplained variation (the SSE) is the distance between the expected value and the linear model.
- Explained variation (the sum of squares regression (SSR)) is the distance from the linear model to the average...