So that was a nice simplification. And then plus, what do you have here? Let's see. You have mu, you have n over n. Those cancel out. So you have plus mu squared. So that was a very nice simplification. And then this simplifies to, can't do much on this side, so the sum from i is equal to 1 to n of x sub i squared over n. And then see, we have minus 2 mu squared plus mu squared.