ABSTRACT
Using measures of central tendency, we can measure the concentration of individual values around the central values, for example, mean, median, mode, geometric mean, and weighted mean. The distribution of the data is measured by these statistics. It is also equally important to know the magni tude of dispersion of observations from the central values for efficient re search work. Study of dispersion, spread, scatter, or variability with refer ence to central values, particularly mean, is very important, and is considered as the major problem of statistical science. Variation among ob servations is universal and unavoidable. If we can account for variability, we can take steps or measures to minimize it, and consequently we can get precise estimates and inferences from the sample data.
