And that's because we've seen this multiple times. The mean of your sampling distribution is going to be the same thing as your population mean. So this is the same thing as that. That is the same thing as that. Or another way of saying it is if we think about the distribution, if we think about the mean of the distribution of the difference of the sample means, and we focused on this in the last video, that that should be equal to 0. Because this thing right over here is the same thing as that right over there. So that is our null hypothesis.