And we're going to do that for the population. So we're going to use mu. So what does the arithmetic mean here? Well, we just have to add all of these data points up and divide by 5. And I'll just get the calculator out just so it's a little bit quicker. And so this is going to be 4 plus 4.2 plus 5 plus 4.3 plus 5.5. And then I'm going to take that sum and then divide by 5.