It's going to be a 1. We just divided a 1, we just divided this by 1, took it out of the sigma sign, out of the sum, and you're just left with a 1 there. And actually, we could have just left the mu squared there. But either way, let's just keep simplifying it. So this we can't really do. Well actually, we could. Well no, we don't know what the x sub i's are, so we just have to leave that the same.