But as you take the limit, you end up with e. And if you think about it, it makes sense, because one of our derivations of e actually came out of compound interest, and we kind of did something similar there. We took smaller and smaller intervals of compounding, and over each interval we compounded by a much smaller number, and when you took the limit, you got e again. And that's actually where that whole formula up here came from to begin with. But anyway, just so that you know how to use this thing, so let's say that I were to go out, I'm the traffic engineer, and I figure out that on average, 9 cars pass per hour. So I want to know the probability that 2 cars pass in a given hour, exactly 2 cars pass, it's going to be equal to 9 cars per hour to the 2th power, or squared, instead of the 2th power, divided by 2 factorial times e to the minus 9 power. So it's equal to 81 over 2 times e to the minus 9 power. And let's see, maybe I should just get the graphing calculator out there.