And given that the null hypothesis is true, we say OK, if the null hypothesis is true, then the mean is usually going to be equal to some value. So we create some distribution assuming that the null hypothesis is true. It normally has some mean value right over there. And then we have some statistic, and we are seeing if the null hypothesis is true, what is the probability of getting that statistic, or getting a result that extreme or more extreme than that statistic? So let's say that the statistic gives us some value over here, and we say, gee, you know what? There's only, I don't know, there might be a 1% chance, there's only a 1% probability of getting a result that extreme or greater. And then if that's, I guess, low enough of a threshold for us, we will reject the null hypothesis.