Source of variation

Sum of squares

Degrees of freedom

Middle square

∑ Y_i²

21,686.22

11

1971.47

Because X₀

10,845.56

1

10,845.56

Because X₁

8843.30

1

8843.30

Because X₂

719.32

1

719.32

Because X₃

0.52

1

0.52

Because X₁₂

1100.28

1

1100.28

Because X₁₃

14.83

1

14.83

Because X₂₃

126.38

1

126.38

Because X₁₂₃

32.79

1

32.79

Residual sum of squares

3.23

3

1.08

Mismatches

−3.23

1

−3.23

Experimental error

6.46

2

3.23