Like sometimes people might assume things like a normal distribution in finance and we see in the financial crisis that's led to a lot of things blowing up. But anyway, let's get back to this. And this is a spreadsheet right here. I just made a black background. And you can download it at, let me write it right here, at khanacademy.org slash downloads. And actually if you just do that, you'll see all of the downloads, I haven't put it there yet, I'm going to do it right after I record the video. This downloads slash normal distribution.