Actual by Predicted Plot for Full Model
The Effect Summary report suggests that a number of effects are not significant. In particular, X2*X3 is the least significant effect with a PValue of 0.99563. Next, you will systematically reduce the model using the Effect Summary report interactively.
Effect Summary Report
Click on X1*X3 and click Remove.
The PValue for X3*X3 indicates that it is not significant.
Click on X3*X3 and click Remove.
Click on X1*X2 and click Remove.
Notice that X3 is not significant. It is not contained in any higher-order effects, so you can remove it without violating the Effect Heredity principle. See Effect Heredity in Standard Least Squares Report and Options.
Click on X3 and click Remove.
Effect Summary Report after Reducing Model

Help created on 9/19/2017