# The mean

**The mean**

The definition of the **mean** is that it is the most commonly used average. The following represents the mean:

Mean = sum of all values ÷ number of values

For example, the mean time for 5 cars accelerating 0 – 60 mph are as follows:

= (12.9 + 9.9 + 15.2 + 10.3 + 6.2) ÷ 5

= 54.5 ÷ 5

= 10.9

**Outliers and their effect on the mean**

Outliers is a data set which is significantly higher or lower than the other items which has the affect of reducing or increasing the mean materially. This therefore would cause a mean to be less accruate.