Arithmetic Mean Concept: 
The purpose of calculating the arithmetic mean is to find the average value of a given set of numbers.  The mean is considered a measure of central tendency.  Two other measures of central tendencies are median and mode.  

Definition of Arithmetic Mean: 
The arithmetic mean, or average, is the sum of the values divided by the number of values.

Arithmetic Mean Formula:

Where:

                         = Sample arithmetic mean

                           = Sample size

                         =   Observation of the  random variable

                    = Summation of all  values in the sample