The Mean

The Mean

By Steve Dallow

Definition

​The Mean

The Mean of a set of numbers in a data set is obtained by adding up all the numbers then dividing by the size of the data set.

Worked Example

Question

A football team played six games.

Here are the number of goals they scored in each game:

6, 0, 3, 2, 2, 5

Find the Mean number of goals.

Worked Example

Answer

Multiple Choice

Here are the ages of people in a family

15, 15, 19, 20, 54, 59

Work out the mean of the ages in this family. Give your answer to 3 significant figures.

• 30

• 30.0

• 30.3

• 31

Multiple Choice

The heights of some children (to the nearest cm) are shown below.

113, 111, 123, 121, 119, 113, 117

Calculate the mean height to 1 decimal place.

• 117.0

• 116.0

• 116.7

• 116.8

• 116.5