So this, already, we've kind of come up with a neat way of writing the variance. You can essentially take the average of the squares of all of the numbers, in this case a population, and then subtract from that the mean squared of your population. So this could be, depending on how you're calculating things, maybe a slightly faster way of calculating the variance. So just playing with a little algebra we got from this thing, where you have to, each time, take each of your data points, subtract the mean from it, and then square it. And then, of course, before you had to do anything, you had to calculate the mean. And you take the square, then you sum it all up, then you take the average, essentially, when you divide it, when you sum and divide it by n. We've simplified it, just using a little bit of algebra, to this formula. And this is, we're getting to something called the raw score method.