These distances between each data point and the group mean are squared and added together to give the residual sum of squares, SSR: (12.13) Equation (12.13) says that the sum of squares for each group is the squared difference between each participant’s score in a group (x ig) and the group mean , and the two sigma signs mean that we repeat this calculation for the first participant (i = 1) through to the last (n), in the first group (g = 1) through to the last (k).
