Table 6. Analysis of variance for a third-order model on Y2

Source DF Sum of squares Mean square F-value Pr>F-value
Model 18 6.11921 0.33996 15.20 0.0003
Error 8 0.17895 0.02237
Lack of fit 6 0.17888 0.02981 894.42 0.0011
Pure error 2 0.00007 0.00003
Corrected total 26 6.29816
Root MSE=0.14956, Dependent mean=5.13704, r2=0.9716, Adj r2=0.9077
Model terms: X1, X2, X3, X4; X12, X22, X32, X42; X1X2, X1X3, X1X4, X2X3, X2X4, X3X4 X13, X23, X33, X43.