Our mean is negative right now. Our mean is minus 5, so it's x plus 5 over the standard deviation squared, which is the variance. So that's 100 squared dx. This is what this number is right here, this 7%, or actually 0.07 is the area right under there. Now, unfortunately for us in the world, this isn't an easy integral to evaluate analytically, even for those of us who know our calculus. So this tends to be done numerically, and kind of an easy way to do this, well, not an easy way, but a function has been defined called the cumulative distribution function that is a useful tool for figuring out this area. So what the cumulative distribution function is essentially, let me call it, cumulative distribution function, it's a function of x.