Source

S (sum of squares)

Φ (DF)

Ψ (mean square)

χ (F value)

τ (Prob. > F)

Model

2.025E+005

19

10,658.92

10.30

0.0006

X₁-collector dose

5512.50

1

5512.50

5.32

0.0464

X₂-pH

8100.00

1

8100.00

7.82

0.0208

X₃-flotation speed

14,400.00

1

14,400.00

13.91

0.0047

X₄-air flow rate

19,600.00

1

19,600.00

18.93

0.0018

X₁X₃

400.00

1

400.00

0.39

0.5496

X₁X₄

4900.00

1

4900.00

4.73

0.0576

X₂X₄

28,900.00

1

28,900.00

27.91

0.0005

X₃X₄

25,600.00

1

25,600.00

24.73

0.0008

$X_1^2$

5194.96

1

5194.96

5.02

0.0518

$X_2^2$

22,046.85

1

22,046.85

21.30

0.0013

$X_3^2$

10,146.18

1

10,146.18

9.80

0.0121

$X_4^2$

36,049.96

1

36,049.96

34.82

0.0002