Table 2.

Central composite design arrangement and responses.

Run	X 1	X 2	X 3	FFAs (%)		Yield (%)
				Actual	Predicted	Actual	Predicted
1	−1	−1	−1	7.25	7.30	18.81	19.99
2	1	−1	−1	1.58	1.60	27.33	28.04
3	−1	1	−1	6.74	6.81	26.32	25.96
4	1	1	−1	1.56	1.45	25.79	27.42
5	−1	−1	1	10.31	10.32	19.35	17.69
6	1	−1	1	1.62	1.44	25.34	25.67
7	−1	1	1	10.23	10.11	24.69	23.95
8	1	1	1	1.72	1.57	26.55	25.34
9	−1.682	0	0	15.98	15.93	18.6	19.52
10	1.682	0	0	3.75	3.95	28.32	27.45
11	0	−1.682	0	2.02	2.03	22.45	22.10
12	0	1.682	0	1.60	1.73	26.45	26.84
13	0	0	−1.682	1.56	1.49	28.6	26.71
14	0	0	1.682	3.91	4.13	21.09	23.03
15	0	0	0	1.58	1.64	26.35	24.53
16	0	0	0	1.65	1.64	24.56	24.53
17	0	0	0	2.18	2.32	21.65	24.53
18	0	0	0	1.76	1.64	26.51	24.53
19	0	0	0	1.68	1.64	24.55	24.53
20	0	0	0	1.01	1.64	23.56	24.53