A box plot is a diagram that clearly shows the minimum and maximum value of a data set along with the three quartiles.

Constructing box plots

Maths

In the prior unit, pupils compared two different sets of data. In this unit, pupils consider cumulative frequency graphs and histograms and compare these with other known graphical representations.

Graphical representations of data: cumulative frequency and histograms

What is the lower quartile of this set of data?  17, 13, 19, 21, 13, 14

Below is a box plot for this set of data: 17, 13, 19, 21, 13, 14. What is the value of point E on the box plot?

Below is a box plot for this set of data: 17, 13, 19, 21, 13, 14. What is the value of point C on the box plot?

Use this graph to estimate the lower quartile.

Use this graph to estimate the upper quartile.

Any pupil scoring over 16 marks gets a certificate.  How many certificates are given out?

Starter Quiz