The GEOMEAN and HARMEAN are advanced statistical functions that typically require a deeper understanding of mathematics. This is probably why they aren't taught as often as the AVERAGE function.

You can find the Average of a value by selecting the cell below or to the right of values that you want to Average. Then go to the Editing Group, select the Auto-Sum Tool. You will see a drop-down ...

This post explains how to calculate Weighted Average in Excel with percentages. In a standard arithmetic average where the sum of values is divided by the number of values, each data value is treated ...