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

The spread/dispersion of data values describes how far apart the pieces of data are.

Understanding and calculating the range

Maths

Checking understanding of the mean

Calculating the mean

Understanding the median

Calculating the median

Understanding the mode

Calculating the mode

Summarising data

Changing a data point

Evaluating the range

Comparing statistical representations

Comparing summaries of data

Analysing different statistical representations

Correlation

Statistical problems - data collection

Statistical problems - statistical summaries

Statistical problems - data presentations

Statistical problems - drawing conclusions

Problem solving with numerical summaries of data

In this unit, pupils consider the mean, median and mode and evaluate their usefulness in a variety of contexts. In the sampling unit, pupils are given the opportunity to consider where the data came from and how it was collected and can therefore start to evaluate how good a representation the sample is of the whole population.

In this unit, pupils learnt how to calculate the mean and began to use the mean to make comparisons between two sets of data. Pupils also considered whether the mean was an appropriate way of representing the data 

In this unit pupils explore the concept of measures of central tendancy, developing understanding of different types of average and their relative benefits and drawbacks. We then investigate other summaries of data such as the range and data comparison techniques.

Numerical summaries of data

The range is a measure of spread. It is found by finding the {{ }} between the two extreme points; the lowest and highest values.

cat, dog, rabbit, dog, cat, rabbit, hamster

Select the data sets where you can calculate a range.

A large data set has the extreme values of 24.6 and 59.2. The range of the data set is {{ }}.

This line graph shows data about journey times to school over a week. The range of the journey times is {{ }} minutes.

Which of these bar charts show data with a range of 4?

Two numbers have a difference of 10. The smaller number is 53. The other number is {{ }}

Two positive numbers have a difference of 8. One of the numbers is 6. The other number is {{ }}

Starter Quiz

Work out: $$ 128 - 94 $$ =