Table 3. Analysis of variance (ANOVA) for fitted models for weight loss of particle board in no-choice test

Source	Sum of squares	df	Mean square	F-value	p-value
Model	5.83	9	0.6477	6.77	0.0243	Significant
X1	0.02	1	0.02	0.2092	0.6666
X2	0.312	1	0.312	3.26	0.1306
X3	2.83	1	2.83	29.62	0.0028
X1.X2	0.0009	1	0.0009	0.0094	0.9265
X1.X3	0.1024	1	0.1024	1.07	0.3482
X2.X3	0.1849	1	0.1849	1.93	0.2231
X12	1.8	1	1.8	18.79	0.0075
X22	0.6748	1	0.6748	7.06	0.0451
X32	0.0083	1	0.0083	0.0871	0.7797
Residual	0.478	5	0.0956
Lack of fit	0.1166	3	0.0389	0.2152	0.8795	Not significant
Pure error	0.3614	2	0.1807
Cor total	6.31	14

R² = 0.924, adjusted R² = 0.789, predicted R² = –0.575, adequate precision = 7.98, SD = 0.309, coefficient of variation = 17.03, mean = 1.82.
X₁, adhesive concentration (%), X₂, wood vinegar concentrations (%) and X₃, ratio of oil palm trunk and sengon wood sawdust.