Comparative Study of Various Measures of Dispersion

Abstract

Statistical is a subject of mathematics, computers, management, business etc. Central tendency and measures of dispersion are two major aspects of statistical methods. Measures of dispersion are the statistical formula to measure the spread of the data about an average basically dispersion is the measure of the variation of the items. Dispersion refer to the variation among different values of a series if all the value of a series are equal then there is no dispersion but if there is wide variation among different values of a series then dispersion is present at the peak, but in other case dispersion refer to the variation of different values of the series around an average if there is no difference between various values and average then there is no dispersion but if various values are widely scattered around average then dispersion is present at the peak. A good Measure of dispersion must be easy to understand, easy to calculate, well defined. A measure of dispersion is capable of algebraic treatment. There are various types of Measures of dispersion like range, mean deviation, standard deviation. Range is the simplest method of dispersion. it is the difference between the largest value and the smallest value of the variable in the series, range is rigidly defined. Mean deviation is the arithmetic average of the deviations of all the values of the series; mean deviation is the average amount of scatter of the items in a distribution from either the mean or the median. Standard deviation is the square root of the arithmetic mean of the squares of all the deviations.