Dispersion is a measure of the extent to which the individual item vary from a central value Dispersion is used in two senses, (i) difference between the extreme items of the series and (ii) average of deviation of items from the mean.
Absolute Measure : The figure showing the limit or magnitude of dispersion is known as absolute measure and it is shown in the same unit as ;those of the original data, exampple e measures of dispersion in the age of students, their height, weight etc.
Relative Measure : For comparative study the concerning absolute measure is divided by the corresponding mean or some other characteristic value to obtain a ratio or percentage, which is known as the relative measure.
