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

The median is the central (middle) piece of data when the data are in numerical order.  It is a measure of central tendency representing the average of the values.

The range is a measure of spread. It is found by finding the difference between the highest and lowest values.

Comparing 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

Anything below the __________ represents 25% of the data.

Anything below the upper quartile represents what percentage of the data?

What is the range of the middle 50% of data?

A {{ }} box indicates data that is more consistent.

The vertical line inside the box of a box plot represents the {{ }}.

What is the height of the tallest person?

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

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

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

Starter Quiz