There are 6 degrees of freedom. Let me write 6 degrees of freedom. In the future, we might do a more detailed discussion of what degrees of freedom mean and how to mathematically think about it. But the simplest way to think about it is really, truly independent data points, assuming you knew, in this case, the central statistic that we use to calculate the squared distance in each of them. If you know them already, the third data point could actually be calculated from the other two. So we have 6 degrees of freedom over here. Now, that was how much of the total variation is due to variation within each sample.