Application of Box-Behnken Design in Optimization of Glucose Production from Oil Palm Empty Fruit Bunch Cellulose

Table 5

Regression analysis of a full second-order polynomial model for optimisation of glucose production from OPEFB cellulose.

Variables	Standard error	𝑡 value	𝑃-value	Coefficient based on coded value
Intercept	5.077401	10.64	0.0001**	54.000000
𝑥1	3.877929	2.37	0.0553	9.200000
𝑥2	4.635012	−2.32	0.0595	−10.750000
𝑥3	3.877929	12.02	0.0001**	46.600000
𝑥1×𝑥1	6.716770	6.30	0.0007**	42.300000
𝑥2×𝑥1	10.154802	−5.82	0.0011**	−59.100000
𝑥2×𝑥2	8.028076	7.19	0.0004**	57.750000
𝑥3×𝑥1	4.397158	3.48	0.0132*	15.300000
𝑥3×𝑥2	6.388923	−6.70	0.0005**	−42.800000
𝑥3×𝑥3				0.000000

∗∗Significant at 1% level.
∗Significant at 5% level.