Or if you don't want to worry about the word population or sample and all of that, both of these data sets have the exact same arithmetic mean. When you average all these numbers and divide by 5, or when you take the sum of these numbers, divide by 5, you get 10, sum of these numbers, divide by 5, you get 10 as well, but clearly these sets of numbers are different. If you just looked at this number, you'd say, oh, maybe these sets are very similar to each other. But when you look at these two data sets, one thing might pop out at you. All of these numbers are very close to 10. I mean, the furthest number here is 2 away from 10. 12 is only 2 away from 10.