Calculating the Mean

To find the mean average of a set of data

The mean is the 'average' of a set of data. To find the mean you must add all of the amounts together and then divide it by the number of items.

e.g. These are the scores 8 children got in a Science test out of 10.

7, 2, 1, 9, 8, 2, 3, 8

7 + 2 + 1 + 9 + 8 + 2 + 3 + 8 = 40

I then divide the answer by 8 as there were 8 sets of data. 40 divided by 8 = 5.

The mean (average) score was 5.

Your turn

Here is the average monthly rainfall in cm of 9 cities in the world for the month of January:
 

8, 7, 5, 3, 7, 1, 3, 2, 9

What is the mean monthly rainfall?

Watch the White Rose video to work through more examples

Your turn: