## Reasoning with data

## Overview

Much of the statistics content in Key Stage 3 is a continuation of that studied at

primary school, and many of the charts and graphs in this half term have been

used in Year 7 and earlier in Year 8. A particular focus is using charts to

compare different distributions. We also explore when graphs may be

misleading, an important real-life consideration. Collection of data is also

covered, including designing and criticising questionnaires.

Students have already met the median and the mean earlier in KS3. This half term

reintroduces the mode and also looks at when and why each average should be

used. Students will also look at the mean from grouped

and ungrouped frequency tables. We also consider outliers, considering what effect

these have on all the measures studied, and whether they should be included or

excluded in our calculations.

## Building on

Rounding (Year 7 Autumn 2)

Range & Median (Year 7 Autumn 2)

Bar Charts (Year 7 Spring 1)

Line Graphs (Year 7 Spring 1)

Mean (Year 7 Spring 1)

Scatter Graphs (Year 8 Autumn 2)

## Powerful Knowledge

Understand and set up a statistical enquiry

Design and criticise questionnaires

Draw and interpret pictograms, bar charts and vertical line charts

Draw and interpret multiple bar charts

Draw and interpret pie charts

Draw and interpret line graphs

Choose the most appropriate diagram for given set of data

Represent and interpret grouped quantitative data

Find and interpret the range

Compare distributions using charts

Identify misleading graphs

Understand and use the mean, median and mode

Choose the most appropriate average

Find the mean from an ungrouped frequency table

Find the mean from an grouped frequency table

Identify outliers

Compare distributions using averages and the range

## Lesson Resources

Lesson 1 – Working with Questionnaires

Lesson 2 – Pictograms

Lesson 3 – Pie Charts (New for 2024 – 25)

Lesson 4 – Which statistical diagram is best?

Lesson 5 – Misleading Graphs

Lesson 6 – Working with the range

Lesson 7 – Mean, mode and median

Lesson 8 – Which average should we use?

Lesson 9 – Outliers

Lesson 10 – Averages from frequency tables

Lesson 11 – Averages from grouped frequency tables

Lesson 12 – Comparing data sets