And I'm actually going to call that the grand mean. I'm going to call that the grand mean. And I'm going to show you in a second that it's the same thing as the mean of the means of each of these data sets. So let's calculate the grand mean. So it's going to be 3 plus 2 plus 1, 3 plus 2 plus 1, plus 5 plus 3 plus 4, plus 5 plus 3 plus 4, plus 5 plus 6 plus 7. Plus 5 plus 6 plus 7. And then we have 9 data points here.