How to Calculate the Mean or Average

Mean and average are two words for the same calculation.
Mean and average are two words for the same calculation. Blend Images - Eric Raptosh Photography, Getty Images

It's important to know how to calculate the mean or average of a set of numbers. Among other things, this will allow you to calculate your grade point average. However, you'll need to calculate the mean for several other situations, too.

The Mean or Average

In general, you calculate the mean or average of a set of numbers by adding them all up and dividing by how many numbers you have. This can be defined as follows:

For a set of numbers, {x1, x2, x3, ... xj} the mean or average is the sum of all "x" divided by "j".

Worked Examples of Calculating the Mean

Let's start with an easy example. Calculate the mean of the following set of numbers:

1, 2, 3, 4, 5

To do this, add up the numbers and divide by how many numbers you have (5 of them, in this case).

mean = (1 + 2 + 3 + 4 + 5)/5

mean = 15/5

mean = 3

Pretty easy, right? Here's another example of calculating the mean.

Calculate the mean of the following set of numbers:

25, 28, 31, 35, 43, 48

How many numbers are there? 6. So, add together all of the numbers and divide the total by 6 in order to get the mean.

mean = (25 + 28 + 31 + 35 + 43 + 48)/6

mean = 210/6

mean = 35

More Calculations and Sample Problems