There are three types of average – mean, median and mode.

And also sort of range.

We’ll get to that.

The mean is calculated by adding all the numbers up, then dividing by the amount of them. Eg: 29,45,81 and 3 have a mean of 39.5.

The mean is good as it represents all the data, but it is also swayed easily by extreme values.

The mode is the most common number in the set. Eg: 2,3,2,4,5,2,1,7,3,2,2,1,2,2 has a mode of 2. 29,45,81,3 has no mode.

While not swayed by extreme values, the mode is not necessarily indicative of the whole set.

The median is the middle number. To find it, you put all the numbers in order, then take the one in the middle. If you have an even number of them, you take what’s halfway between the two middle numbers.

The median is unaffected by extreme values but also doesn’t represent the whole set.

Range is sort of an average, though not really. It is the largest number minus the smallest number. It doesn’t really have anything to do with the numbers themselves though, which is why its not always though of as an average.