So we are now talking about this whole area. And area is key. So if you want to know the probability of this occurring, you actually want the area under this curve from this point to this point. And for those of you who have studied your calculus, that would essentially be the definite integral of this probability density function from this point to this point. So from, let me see, I've run out of space down here. So let's say if this graph, let me draw it in a different color, if this line was defined by, I don't know, I'll call it f of x. I could call it p of x or something. The probability of this happening would be equal to the integral, for those of you who have studied calculus, from 1.9 to 2.1 of f of x dx, assuming this is the x-axis.