Question

In an effort to stabilize the process, there has been some discussion about 3 machines
that appear to be causing variation in the mean part thicknesses (measured
prior to plating). It appears that these 3 machines may be producing parts with different average
material thickness even though they are supposed to be producing parts with the same average thickness.
It was suggested that a One-Way ANOVA be used to compare the mean thicknesses
produced by these 3 machines. You will be checking for significant differences between
the mean material thicknesses produced by these 3 machines. Use a 5% level of significance.
Data:
	Machine 1	Machine 2	Machine 3
	0.546	0.573	0.573
	0.526	0.592	0.570
	0.587	0.571	0.527
	0.563	0.556	0.572
Question:
Calculate Correction for the Mean (CM)
I got	3.803628

Answer 1

$CM= \frac{(Grand total)^2}{Total\ number \ of \ data}=\frac{(0.546+0.573+----\ +0.572)^2 }{12}$

  $=\boldsymbol{3.803628 }$