Or if we want to speak generally, into m different groups. What I want to do in this video is to figure out how much of this total sum of squares, how much of this is due to variation within each group versus variation between the actual groups. So first, let's figure out the total variation within the group. So let's call that the sum of squares within. So let's calculate the sum of squares within. And I'll do that in yellow. I actually already used yellow.