You can use the **Variables** tab to specify the variables for the Polynomial Regression analysis.

The **Variables** tab is shown in FigureĀ 20.3. The Y variable is the response variable. The dialog box supports a single X (explanatory) variable. To analyze a response
that depends on multiple explanatory variables, you can use the Linear Regression (see ChapterĀ 21: Model Fitting: Linear Regression) or the Generalized Linear Models (see ChapterĀ 24: Model Fitting: Generalized Linear Models) analysis.