## Mean Definition

The mathematical definition of mean is quite simple- it is the average of a set of numbers. However, calculating the mean can be difficult when there are a lot of numbers involved. The easiest way to calculate the mean is to add up all of the numbers in the set and then divide by the number of items in the set. For example, if you have a set of 5 numbers: 1, 2, 3, 4, and 5; the mean would be ((1+2+3+4+5)/5), which equals 3.