The Mean or Average
In general, you caculate the mean or average of a set of numbers by adding them all up and divding by how many numbers you have. This can be defined as follows:For a set of numbers, {x
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
Worked Examples of Calculating the Mean
Let's start with an easy example. Calculate the mean of the following set of numbers:

