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Measure of Variability
The average is after all a single numerical value and may fail to reveal the data entirely. Thus after measuring the central tendency, the next step is to find some measure of variability of data. Variability is the spread or scatter of the separate scores around their central tendency.
Measures of Dispersion Percentile
We discussed the commonly used measures of central tendency which are useful in providing descriptive information concerning a set of data. However, the information so obtained is neither exhaustive nor comprehensive, as the mean does not lead us to know whether the observations are close to each other or far apart. Median is the positional average and has nothing to do with the variability of the observations ...
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