And I gave you an intuition of why many, many videos ago. We divide by 100 minus 1. We divide by 100 minus 1, or 99. Let's get the calculator out to actually figure out our sample variance. Let me get the calculator out. And we have, so I'll do the numerator first. I have 57 times 0 minus 0.43 squared plus 43 times 1 minus 0.43 squared.