Five-number summary

Definition

The five-number summary describes a data set with five values: the minimum, the lower quartile (Q1), the median, the upper quartile (Q3) and the maximum. It is drawn as a box-and-whisker plot.

Worked example

For 2; 4; 4; 6; 8; 9; 10 the five-number summary is 2; 4; 6; 9; 10.

In the box-and-whisker plot, the box runs from Q1 = 4 to Q3 = 9 with a line at the median 6, and the whiskers reach 2 and 10.

Where it appears in the exam

Five-number summary is part of the statistics section of CAPS Grade 10 Mathematics and is examined in Paper 2 of the November exam.

Step-by-step method

1. Sort the data from smallest to largest.
2. Write down the minimum and maximum.
3. Find the median.
4. Find Q1 and Q3 as the medians of the lower and upper halves.

Common mistake

Drawing a box-and-whisker plot without a scale, so the values can't be read.

Related statistics terms

• Standard deviation
• Least squares regression line
• Correlation coefficient
• Outlier
• Interquartile range
• Ogive

Frequently asked questions

What does five-number summary mean in Grade 10 Maths?

The five-number summary describes a data set with five values: the minimum, the lower quartile (Q1), the median, the upper quartile (Q3) and the maximum. It is drawn as a box-and-whisker plot.

Which paper tests five-number summary in Grade 10?

Five-number summary belongs to the Statistics section of CAPS Grade 10 Mathematics, which is examined in Paper 2 of the November exam.

How do I practise questions involving five-number summary?

Snap a question that uses five-number summary into Snap&Learn with your grade set to Grade 10, or work through the Grade 10 topic guide and practice papers.