# How to Find the Geometric Mean

The geometric mean of two numbers is the square root of their product. More generally, it is the “nth” root of the product of n numbers.

### Instructions

- Step 1:
**Take the square root for two numbers**Take the square root of the product if you are only dealing with two numbers. This is the geometric mean when there are only two numbers. - TIP: The geometric mean of 2 and 72 is the square root of their product, or 12.
- Step 2:
**Determine logarithms for more than two numbers**If you are dealing with more than two numbers, determine the logarithm of each number that will be multiplied. Use the logarithmic function key on your calculator to calculate these values. - Step 3:
**Add the values**Add each of these logarithmic values together. - Step 4:
**Divide by the number of values**Divide the sum of the logarithmic values by the total number of values. - Step 5:
**Determine the antilog value**Determine the antilog value of the average using the antilogarithm function key on your calculator. This is the geometric mean for the general case. - FACT: Health inspectors often report bacteria concentrations at public beaches as geometric means so that very high or very low numbers don’t skew the average.

### You Will Need

- A set of numbers
- A calculator with advanced math functions