Table 5.

Response surface design and its experimental response.

Trials	CuSO4.5H2O	(NH4)2SO4	K2HPO4	Antibacterial activity (Inhibition zone in mm ± s.e.m.)
1	−	−	0	22 ± 2.64
2	+	−	0	6 ± 2.64
3	−	+	0	21 ± 0.57
4	+	+	0	6 ± 1.52
5	−	0	−	20 ± 0
6	+	0	−	24 ± 0
7	−	0	+	23 ± 3.78
8	+	0	+	6 ± 2.08
9	0	−	−	28 ± 0.57
10	0	+	−	6 ± 0.57
11	0	−	+	9 ± 1.52
12	0	+	+	9 ± 3.05
13	0	0	0	12 ± 1.15
14	0	0	0	8 ± 2.51
15	0	0	0	6 ± 4.04
16	0	0	0	7 ± 6.80
17	0	0	0	28 ± 5.68