Stat Unit

In the first set of columns, we've computed the sum of squared deviations from the mean. In the second set of columns, we've computed the sum of squared deviations from the constant 4. In the third set of columns, we've computed the sum of squared deviations from the constant 2.

While the sum of squared deviations from the mean equals 10, the sum of squared deviations from the constants 4 and 2 equals 15. In other words, the sum of squared deviations from the mean is SMALLER than the sum of squared deviations from the either the constant 4 or 2.

You should take the time to confirm this property for yourself. You might, for example, subtract a constant of one from every term in the distribution. If you do, you will verify that the sum of squared deviations from the mean is SMALLER than the sum of squared deviations from the constant one.

At the moment, this property of the mean appears rather useless. And while it is true this property has no immediate value for us, its value will become apparent in later units.