The Mean

The mean is a measure of centre which is often regarded as the ‘average’. The mean of a data set is given by:

\bar{x}= \frac{\sum{x}}{n}

  • \bar{x}= mean of the data values
  • \sum{x} = sum of all the data values
  • n= total number of data values


Consider the set of data


The mean of this set of data is

mean = \frac{3+7+1+9+12}{5} = 6.4

See also: