The variance of x bar plus the variance of y bar. Now, actually, let me just draw this here, just so we can visualize another distribution. Although, all I'm going to draw is another normal distribution. So this is its mean. So the mean over here, let me scroll down a little bit. So the mean over here, mean of x bar minus y bar, is going to be equal to the difference of these means over here. So I have to rewrite it.