The difference between each of these, 6 minus 4 is 2, squared is 4. So we have 3 times 4 plus 3 times 4. And we get 3 times 4 is 12 plus 0 plus 12 is equal to 24. So the sum of squares, or we could say the variation due to what's the difference between the groups, between the means, is 24. Now, let's put it all together. We said that the total variation, that if you look at all nine data points, is 30. Let me write that over here.