Explain the difference between dispersion and skewness.
Explain the difference between dispersion and skewness.
Ans.
Following is the difference between dispersion and Skewness–
(i) Dispersion depicts the scatteredness or dispersal of values from a measure of central tendency, but measures of skewness show whether the distribution is symmetrical or asymmetrical. It indicates the shape of the frequency curve. Thus under dispersion composition of group is studied, while formation of series is studied under dispersion.
(ii) Measures of dispersion reveals the scatter or spread of complete series, but they do not reveal on which side of the central value, the values have more variation. But measures of skewness indicate the direction of variation, that is, variations on the two sides of median are known. Because of this, the skewness may be positive or negative.
(iii) Measures of dispersion are based upon the averages of the first order. These are called averages of the second order. On the contrary measure and coefficient of skewness are based on averages of first and second order. In other words, these are determined on. the basis of measures of central tendency and measures of dispersion, both.
(iv) Measures of dispersion are based on first, second and third moments. On the contrary, measure of skewness is ascertained on the basis of first and third moments.
(v) Measures of dispersion indicate the extent to which they represent the series. While measures of skewness indicate about the symmetry or asymmetry of the series. It also reveals the direction of asymmetry-positive or negative.
(vi) Measures of dispersion are used monthly for the study of problems in the field of economics and social, while measures of skewness are used mostly for the study in the field of physics and zoology.
