Measures of variability

Variance, standard deviation, and interquartile range

There are three primary measures of variability. Variability, as a statistical concept, is extremely important. Variance dictates the statistical power and statistical precision with which study results can be generalized. Standard deviation gives a relative context to observations in a distribution. And interquartile range plays a significant role in better understanding the effects of skewed distributions. Measures of variability are often reported concurrently with measures of central tendency like means and medians. 

Three measures of variability

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There are three measures of variability: Variance, standard deviation, and interquartile range (IQR).