# What is the measure of dispersion in statistics?

## Measure of dispersion

Measure of dispersion

• In statistics, dispersion (also called variability, scatter, or spread) is the extent to which a data distribution is stretched or squeezed.
• In other words, dispersion is the extent to which values in a distribution differ from the average of the distribution.
• It gives us an idea about the extent to which individual items vary from one another, and from the central value.
• It is the indication of scattering or spreading or variability of the data.
• Common examples of measures of statistical dispersion are

Range and interquartile range
Variance
Standard deviation

## Types or Classification of Measures of Dispersion

### An absolute measures of dispersion

• The measures which express the scattering of observation in terms of distances i.e., range, quartile deviation.
• The measure which expresses the variations in terms of the average of deviations of observations like mean deviation and standard deviation.

### A relative measures of dispersion

• A relative measure of dispersion for comparing distributions of two or more data set and for unit-free comparison.
• They are the coefficient of range, the coefficient of mean deviation, the coefficient of quartile deviation, the coefficient of variation, and the coefficient of standard deviation.

## Characteristics of Measure of Dispersion

• It have the same units as the quantity being measured.
• It shows the homogeneity or the heterogeneity of the distributionmof the observations.
• When a data set has a large value, the values in the set are widely scattered; when it is small the items in the set are tightly clustered.
• They are rigidly defined, not affected by extreme values, and not affected by sampling fluctuations.
• Measures of dispersion are type of descriptive statistics that describe how similar a set of scores are to each other.
• The more similar the scores are to each other, the lower the measure of dispersion.
• The less similar the scores are to each other, the higher the measure of dispersion.

Example 1: Find the Standard deviation for the following set of sample data by the direct method.

Solution: Substitute the values in the equation and find out SD

Make sure check our amazing article on: Measures of central tendency