- 5-Number Summary
- Minimum, \(Q_1\), Median, \(Q_3\), Maximum
- \(Q_1\) is the first quartile, this is the 25th percentile
- \(Q_3\) is the third quartile, this is the 75th percentile
Five number summaries are used to describe some of the key features of a distribution. Using the values in a five number summary we can also compute the range and interquartile range.
- Range
-
The difference between the maximum and minimum values.
\(Range = Maximum - Minimum\)
Note! The range is heavily influenced by outliers. For this reason, the interquartile range is often preferred because it is resistant to outliers.
- Interquartile range (IQR)
-
The difference between the first and third quartiles.
\(IQR = Q_3 - Q_1\)