The mean of x bar, which is the mean of x minus, or a sample from the sampling distribution of x, or the sample mean of x, minus the sample mean of y. So the mean of this is going to be equal to, and we saw this in the last video. In fact, I think I still have the work up here. Yeah, I still have the work right up here. The mean of the difference is going to be the difference of the means. The mean of the difference is the same thing as the difference of the means. So the mean of this new distribution right over here is going to be the same thing as it's going to be the mean of our sample mean minus the mean of our sample mean of y.