Trial

No.

Coded variablesa

Uncoded variables

The forward extraction

yield (%)

A

B

C

D

A

B

C

D

Experimental

Predicted

1

−1

−1

0

0

33

5

0.015

2.1

65.23

64.81

2

1

−1

0

0

45

5

0.015

2.1

69.2

68.64

3

−1

1

0

0

33

5.8

0.015

2.1

75.5

76.05

4

1

1

0

0

45

5.8

0.015

2.1

72.58

72.99

5

0

0

−1

−1

39

5.4

0.01

1.9

76.1

76.34

6

0

0

1

−1

39

5.4

0.02

1.9

73.24

72.52

7

0

0

−1

1

39

5.4

0.01

2.3

70.9

71.61

8

0

0

1

1

39

5.4

0.02

2.3

72.1

71.85

9

−1

0

0

−1

33

5.4

0.015

1.9

72.28

73.84

10

1

0

0

−1

45

5.4

0.015

1.9

66.23

69.71

11

−1

0

0

1

33

5.4

0.015

2.3

70.23

66.63

12

1

0

0

1

45

5.4

0.015

2.3

73.21

71.53

13

0

−1

−1

0

39

5

0.01

2.1

71.22

71.72

14

0

1

−1

0

39

5.8

0.01

2.1

79.23

76.62

15

0

−1

1

0

39

5

0.02

2.1

64.55

67.03

16

0

1

1

0

39

5.8

0.02

2.1

78.36

77.73

17

−1

0

−1

0

33

5.4

0.01

2.1

69.5

70.97

18

1

0

−1

0

45

5.4

0.01

2.1

74.23

73.92

19

−1

0

1

0

33

5.4

0.02

2.1

71.3

71.75

20

1

0

1

0

45

5.4

0.02

2.1

70.89

69.56

21

0

−1

0

−1

39

5

0.015

1.9

78.3

74.96

22

0

1

0

−1

39

5.8

0.015

1.9

73.25

72.04

23

0

−1

0

1

39

5

0.015

2.3

60.2

61.55

24

0

1

0

1

39

5.8

0.015

2.3

76.58

80.06

25

0

0

0

0

39

5.4

0.015

2.1

80.2

82.24

26

0

0

0

0

39

5.4

0.015

2.1

82.56

82.24

27

0

0

0

0

39

5.4

0.015

2.1

83.26

82.24

28

0

0

0

0

39

5.4

0.015

2.1

82.9

82.24

29

0

0

0

0

39

5.4

0.015

2.1

82.3

82.24