If you were asked, "What is the average value of 2 and 4?" you would probably answer before really thinking, "The answer is 3."  But that is not always true.  Although the arithmetic average value is the most commonly used, many methods of averaging two numbers exist.

arithmetic average value. For n elements:

geometric average value. For n elements:

harmonic average value. For n elements:

square average value. For n elements:

To calculate the various average values for {2,4} and {3,4,5,6}, the work would be as follows:

After all of this work, we can see the following relationship: