Arithmetic Mean or Average is one of the measurements of central tendencies of a given data. The average is supposed to be significant, if the data is not dispersed or the standard deviation of the data is low.

‘Average’ is a very simple but effective way of representing an entire group by a single value.

\[\color{#3b4fb6}{{\rm{Average}}\;{\rm{ = }}\;\frac{{{\rm{Sum}}{\mkern 1mu} \;{\rm{of}}{\mkern 1mu} \;{\rm{given}}\;\;{\rm{quantities}}}}{{{\rm{Number}}{\mkern 1mu} \;{\rm{of}}{\mkern 1mu} \;{\rm{quantities}}}}}\]

For example average of \({a_1},\,{a_2},\,{a_3},.....{a_n}\) will be: \[\color{#3b4fb6}{\frac{{{a_1} + {a_2} + {a_3} + ....... + {a_n}}}{n}}\]

To calculate the sum of quantities, they should be in the same unit.