Now let's look at two sets of values. In my first set I have 21012, in my second set I have negative two, two negative 1012. I want to take the average of, or find the average of this set. And this set, well, I add up all my values, divide them by five and get six over five. And the same thing for this guy, negative one, negative one, negative two minus negative one plus zero, plus one plus two divided by five. Well, these guys cancel and I get zero.