Table : TABLE 12-7. Calculating the Between-Groups Sum of Squares The between-groups sum of squares is calculated by subtracting the grand mean from the sample mean for every score to create deviations, then squaring the deviations and summing the squared deviations. The individual scores themselves are not involved in any calculations.

Sample	X	(M − GM)	(M − GM)²
Foraging	28	−6.135	37.638
	36	−6.135	37.638
	38	−6.135	37.638
M_for = 33.250	31	−6.135	37.638
Farming	32	−4.385	19.228
	33	−4.385	19.228
M_farm = 35.000	40	−4.385	19.228
Natural resources	47	7.948	63.171
	43	7.948	63.171
M_nr = 47.333	52	7.948	63.171
Industrial	40	4.615	21.298
	47	4.615	21.298
M_ind = 44.0001	45	4.615	21.298
	GM = 39.385		SS_between = 461.643