Table 3. Analysis of variance for the second-order model on Y2

Source DF Sum of squares Mean square F-value Pr>F-value
Model 14 5.70276 0.40734 8.21 0.0004
Error 12 0.59540 0.04962
Lack of fit 10 0.59533 0.05953 1,786.00 0.0006
Pure error 2 0.00007 0.00003
Corrected total 26 6.29816
Root MSE=0.22275, Dependent mean=5.13704, r2=0.9055, Adj r2=0.7952
Model terms: X1, X2, X3, X4; X12, X22, X32, X42; X1X2, X1X3, X1X4, X2X3, X2X4, X3X4.