Three measures of central tendency are :
(i) Mean
(ii) Median
(iii) Mode
(i) Mean : The mean is the average of all numbers.
The mean of n quantities x1, x2, x3, .......xn
Median : It is defined as the middle most or the central value of the variable in a set of observations, when the observations are arranged either in ascending or descending order of their magnitudes.
Mode : The item which occurs most frequently i.e., maximum number of times is called mode.
