Arithmetic Average or Mean

The arithmetic mean is the most widely and the most generally understandable of all the averages. This is clear from the reason that when the term   mean is used alone it always refers to the arithmetic mean. According to croxton and Cowden ,The arithmetic  mean of a series  of items is obtained by adding the value of the items and dividing by the numbers of  in the words of H Sadist , Arithmetic mean  is the amount secured by living  the sum of values of the  items in a series by their number  F. C.Mills says  the arrhythmic mean is the centre of gravity of a distribution .

Kinds of Arithmetic Mean: The arithmetic mean is of two kinds

(1)   Simple Arithmetic Mean

(2)   Weighted Arithmetic Mean

(1)   Simple Arithmetic Mean: When all the values of a statistical series are given equal importance, the values is divided by number of items it is called simple Arithmetic Mean. 

(2) Weighted Arithmetic Mean:  Sometimes a statistical series comprises of different values of different importance. As such it becomes essential to give weight age to different values according to their relative important which are called weight. As such the different values are multiplied with their respective weight. The total of the product so obtained is divided by the total of weights.  The quotient is called weighted arithmetic mean.