4.2 & 4.3 Cumulative Frequency & Box Plots

Looking at the Spread of Data - This topic is all about these two related tools for helping us look at how a data set is spread out. Learn about filling in cumulative frequency tables, plotting the corresponding curves and using the curves to draw box plots and answer questions about the data set. See below for some short, specific video lessons, some revision slides and practice questions.

Key Concepts

In this unit you should learn to...

Construct cumulative frequency tables and diagrams
Use them to find the median, quartile, percentiles, range and Interquartile range
Produce and understand box plots
Use all of the above to describe, interpret and compare data sets

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Essentials

Slide Gallery

Look at the topic at a glance with these overview slides about cumulative frequency and box plots

Video Lessons

This section offers a series of video tutorials on this topic. They are carefully paced and ordered to help you step by step through the idea. You can use them to teach yourself from scratch or to review all or any part of the topic as and when you need to.

1. What is Cumulative Frequency

This is an introduction to the concept and purpose of this subtopic.

2. Drawing and using cumulative Frequency curves

In this video we will go through the stages of how to construct the cumulative frequency diagram, from plotting the points to drawing the curve. Then we will have a look at how the diagram can be used.

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3. Interpreting cumulative frequency curves

Once we have the cumulative frequency diagrams, this is a video about how to interpret them.

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4. Curves to box plots

This video covers going from cumulative frequency curves to box plots.

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Summary

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Test yourself

Self Checking Quiz

Practice your understanding on these quiz questions. Check your answers when you are done and read the worked solutions when you get stuck. If you find there are still some gaps in your understanding then go back to the videos above.