And 6.5 divided by 5 is equal to 1.3. So when we calculate our sample variance, this technique, which is the more mainstream technique. And I know it seems voodoo. Why are we dividing by n minus 1? Well, for population variance, we divide by n. But remember, we're trying to estimate the population variance. And it turns out that this is a better estimate. Because this calculation is underestimating what the population variance is.