So what the cumulative distribution function is essentially, let me call it, cumulative distribution function, it's a function of x. It gives us the area under the curve, under this curve, so let's say that this is x right here, that's our x. It tells you the area under the curve up to x. Or so another way to think about it, it tells you what is the probability that you land at some value less than your x value, so it's the area from minus infinity to x of our probability density function, dx. And there's actually an Excel, when you actually use the Excel normal distribution function, you say norm distribution, you have to give it your x value, you give it the mean, you give it the standard deviation, and then you say whether you want the cumulative distribution, in which case you say true, or you want just this normal distribution, which you say false. So if you wanted to graph this right here, you would say false, in caps. If you wanted to graph the cumulative distribution function, which I do down here, let me move this down a little bit, let me get out of the pen tool, so the cumulative distribution function is right over here, then you say true when you make that Excel call.