Measures of Central Tendency
Arithmetic Mean (Or Average)
Mean of ungrouped data or discrete series
Mean for grouped data or continuous series
Combined mean
Weighted mean
Weighted mean refers to the average when different items of a series are given different weights according to their relative importance.
Median
L = lower limit of class in which particular quartile lies
F = frequency of the class interval in which quartile lies
h= class interval of the class in which quartile lies
C = cumulative frequency of the class preceding the class in which quartile lies