Arithmetic Mean

Arithmetic Mean, or Arithmetic Average is the value obtained by dividing the sum of various values  of series by number of items in series.
So to Define Arithmetic Mean, we say that Arithmetic Mean is the tool to measure central tendency of data. We use symbol '∑' to represent total sum of readings of given data. It is called as SIGMA. Thus we say that ∑X is written in place of 'n' items in given data. So to find Arithmetic Mean of given data, we use formula given by: Arithmetic Mean = ∑ X / N.
In case of continuous or grouped frequency distribution, value of 'x' is taken as mid Point of corresponding class. Use of arithmetic mean is very simple and it can be calculated very easily, so it is commonly used in study and analysis of business and economy. In case we are dealing with certain data related to average income, average expenditure, average profit, average loss, wages, incomes and other fields like average score of child, then that the data used can be converted to their average means.
There is another method of finding and computing A. M., which we call as short cut method of computing mean. Here we will first find the assumed mean of given data. So we can find arithmetic mean by using following method:
A.M. = A + ∑ d / N.
Here we say that 'A' is assumed mean or arbitrarily selected value, d = deviation of each value from given assumed mean.