# Statistics interview question: What is the main purpose of a measure of dispersion?

I have been studying statistics for a few years now and feel as if I have gotten to grips with some of the basic principles, such as the measure of variability, or dispersion.

A measure of dispersion indicates the scattering of data. It explains the disparity of data from other data, giving a precise view of their distribution. The measure of dispersion gives us an idea of variation and central value of an individual item. Dispersion is the extent to which values in a distribution differ from the average of the distribution.

Dispersion can be measured in a number of numerical ways, including:-

- Range is the given measure of how spread apart the elements in a dataset are.
- Percentiles tell about the spread of a dataset sectioned off into a predefined percentage.
- Quartiles tell us about the spread of a dataset into quarters, just like the median breaks it in half. IQR is a measure of variability based on dividing the dataset into quartiles.
- Variance describes how much a random variable differs from its expected value. It entails computing squares of deviations.
- Standard deviation is the measure of dispersion of a set of data from the mean.