I also am interested in estimating my population variance. So once again, since we can't survey everyone in the population, this is pretty much impossible to know. But we're going to attempt to estimate this parameter. We attempted to estimate the mean. Now we will also attempt to estimate this parameter, this variance parameter. So how would you do it? Well, reasonable logic would say, well, maybe we'll do the same thing with the sample as we would have done with the population.