The way you actually figure out the probability of, let's say, between 4.5 and 5.5, what is the probability, this is whatever, the odds of me getting between 4.5 and 5.5 inches of rain tomorrow. It'll actually be the integral from 4.5 to 5.5 of this probability density function, or of this probability density function, dx. So that's just the area of the curve. For those of you who don't know calculus yet, I encourage you to watch that playlist. But all this is, is saying the area of the curve from here to here. And actually, it turns out for the normal distribution, this isn't an easy thing to evaluate analytically. And so you do it numerically.