To find the mean is simply to find the find the average of the data provided. You first take all the numbers in the data provided and add them all up and then divide by the number of numbers.

For Example given the following numbers: 13, 18, 13, 14, 13, 16, 14, 21, 13

To find their mean first get their sum: (13 + 18 + 13 + 14 + 13 + 16 + 14
+ 21 + 13) = 135

The divide by the number of numbers ie 9 : 135/ 9 = 15