What is a geometric mean, and how is it different from a "regular" mean?
The geometric mean is not the arithmetic mean and it is not a simple average. It is the nth root of the product of n numbers. In layman's terms, that means you multiply a bunch of numbers together, and then take the nth root, where n is the number of values you just multiplied. If you multiplied two numbers, you take the square root. If you multiplied three numbers you take the cubic root.
Did that make sense? Here's a quick example:
What is the geometric mean of 2, 8 and 4?
Multiply those numbers together. Then take the third root (cube root) because there are 3 numbers.2∗8∗4−−−−−−√3=4