Measures of Dispersion of a data provide an idea of how observations spread out (or) scattered throughout the data.
Measures of Dispersion is also known as Measures of Variation.
Different Measures of Dispersion:
The different measures of dispersion are:
  1. Range
  2. Mean Deviation
  3. Quartile Deviation
  4. Standard Deviation
  5. Variance
  6. Coefficient of Variation
Let us discuss what is a range for a given set of data.
The difference between the largest value and the smallest value in the given set of data is called Range.
Range \(R\) \(=\) Largest value \(L\) \(-\) Smallest value \(S\)
Coefficient of range \(=\) \(\frac{L - S}{L + S}\)
Find the range of the given data: \(23, 64, 56, 42, 11\).
Largest value \(L\) \(=\) \(64\)
Smallest value \(S\) \(=\) \(11\)
Range \(R\) \(=\) \(L - S\)
\(=\) \(64 - 11\)
\(=\) \(53\)
Therefore, the of the given set of data is \(53\).
If the given data represented using class interval has the frequency of initial class as zero, then the next class will be considered for the calculation of range.