A data point that is extremely large or small compared to the rest of the dataset.

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

Describes how far apart pieces of data in a dataset are.

Evaluating the range

Maths

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

An outlier is always the largest value in a data set.

An outlier is extremely large or small compared to the rest of the data set.

An outlier is an extremely large or small value after a range is calculated.

Outliers lie close to all the other data points in a data set.

Outliers lie far away from where the majority of the data points are clustered.

Which of these sentences best describe what an outlier is.

What is the value of the outlier on this dot plot?

How many outliers are there on this dot plot?

Match each piece of information to its value.

For this ordered data set, calculate the range whilst including all outliers, and also calculate the range without the outliers. The difference between the two ranges is {{ }}

An outlier of 28 for number of days in a month without rain.

A student walked 200 km to the supermarket.

19 cats had a mass of 4 - 6 kg. Outlier had a mass of 11 kg.

Different outliers may need to be: kept, removed, investigated further, depending on the context with which these outliers have occurred. Match what should happen to the outlier to its context.

It is found by finding the difference between the highest and lowest values

It is found by putting a data set into size order and finding the middle value

Which of these sentences describe the range?

Match the key parts of a calculation for the range with the correct values for this data set: 6, 3, 10, 4, 9, 1, 4

$${{19 + 12 + 16 + 19 + 9 + 11}\over{6}} = 14.\dot3$$

Select the correct calculation to find the range of this data set: 19, 12, 16, 19, 9, 11

A data set is presented on a dot plot. The range of the data is {{ }}.

Which of these dot plots have a range of 6?

Starter Quiz