4 Data exploration
4.4 Measures of central tendency

The best way to summarize a data set with a single value is to find the most representative value, the one that indicates where the centre of the distribution is. This is called the central tendency. The three most commonly used measures of central tendency are

• The arithmetic mean, which is the sum of all values divided by the number of values,
• The median, which is the middle value when all values are arranged in increasing order,
• The mode, which is the most typical value, the one that appears the most often in the data set.

In the following sections, the way to calculate these three measures will be explained with the help of examples.