Watch the animation for calculating mean and then consider the question below.

Why use this technique? Is it appropriate?

The mean is the most common measure of central tendency. It is sometimes referred to as the ‘average’. Calculating the mean is a way to summarise values when you have a large set of data that is evenly spread and does not include anomalies. For instance if you wanted to find the average temperature over a month then calculating the mean would be the most useful.

Evaluate the strengths and limitations of using mean.


Strengths of Using the Mean –

  • All the data is used to find the answer i.e. all the data is taken into account.
  • This technique works really well when there is a relatively narrow data range.
  • It gives a simple overview of the set of data that has been collected.
  • Further calculations can be made from the result.

Weaknesses of using the mean –

  • Very large or small numbers (anomalies) can distort the result, meaning the answer is much lower/higher than it should be. Therefore, the mean will not be representative of the whole data set. This is especially true if the sample size is small.

When is the mean an inappropriate statistical calculation to use? Watch the animation and consider the question below.

What would be the median value for GDP per capita for these Sub – Saharan African countries?
Is this a more accurate figure that shows the true central tendency of GDP per capita in Sub – Saharan Africa?