extremely significantP < 0.0001
The equation was as follows: Y = 0.75 + 0.09 X 1 + 0.17 X 2 + 0.28 X 3 − 0.32 X 1 X 2 + 0.53 X 1 X 3 + 0.32 X 2 X 3 − 0.48 X 1 2 − 1.11 X 2 2 − 0.83 X 3 2 An analysis of variance analysis found the model group was extremely significant ( P < 0.0001) and the lack of fit was not obvious ( p > 0.05), R 2 = 0.9993, R adj 2 = 0.9984, as shown in Table 4 ; thus, the model could make a scientific analysis of most of the changes in response values.