## Measures of Central Tendency or Averages

Arithmetic Mean
• The arithmetic mean of a set of numbers is the sum of numbers divided by the number of numbers in the set : Mean = sum of the numbers/number of numbers
• It is most the reliable measure provided there are no extreme values in the data because all the values in the data are used in calculating.
• Whenever the set of data contains extreme values, the median or mode would probably be more reliable because they are not influenced by extreme values.
Mode
• The number which occurs most frequently in a set of numbers
• It is most useful in business planning as a measure of popularity that reflects central tendency or opinion.
Median
• May be preferred as a measure of central tendency for describing economic, sociological and educational data.
• The median is popular in the study of social sciences because much of the data in the social sciences contain extreme values, in the set of household incomes.
• Median for an odd number of numbers is the middle number when the numbers are arranged in order of magnitude (i.e. ascending/descending order)
• Median for an even number of numbers is the mean of the two middle numbers when the numbers are arranged in order of magnitude
Listen to the following song for key concepts on Mean, Median or Mode.

Simple Activity
Go through the simple activity on Mean, Median, Mode and Range from this site.