I have mentioned “degrees of freedom” but I wrote that we would address it later. Later is now. Below is part of what I wrote while explaining the basics of the sample variance statistic:
- To get the variance, we do the following…(don't worry about why 1 is subtracted from the sample size for now.)
- The symbol for the sample variance is .
- Here is the sample variance calculation in math shorthand.
Notice again that the formula for sample variance has as a denominator. This term is the degrees of freedom.1 In the above formula, the degrees ...