Reduce the Model

The Make Model button enters the model for the listed terms in a Fit Model specification window. To run the model directly using standard least squares, click the Run Model button.

1. Click Run Model.

The Actual by Predicted Plot shows no lack of fit. The Effect Summary report suggests that you can reduce the model further.

Figure 8.5 Actual by Predicted Plot and Effect Summary Report 

2. Select Methanol*Ethanol in the Effect Summary report and click Remove.

Methanol*Time has p-value 0.33750. Remove it next.

3. Select Methanol*Time in the Effect Summary report and click Remove.

Ethanol*Ethanol has p-value 0.15885. Remove it next.

4. Select Ethanol*Ethanol in the Effect Summary report and click Remove.

Figure 8.6 Effect Summary Report Showing Effects in Final Model 

The remaining effects are significant. You conclude that these are the active effects.