Evaluating the range
I can evaluate the range as a measure of spread, including a consideration of outliers.
Evaluating the range
I can evaluate the range as a measure of spread, including a consideration of outliers.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- The range can be affected by outliers in the data.
- Removing these outliers will change the value of the range.
- Outliers must be carefully considered and only removed if they were recorded in error.
Keywords
Outlier - A data point that is extremely large or small compared to the rest of the dataset.
Range - A measure of spread. It is found by finding the difference between the highest and lowest values.
Spread/dispersion - Describes how far apart pieces of data in a dataset are.
Common misconception
"Adding or removing a data point from a dataset will always change the value of the range"
The range only changes if: the data point added becomes a new max or min value, or the data point removed is the current max or min value.
Licence
Lesson video
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Starter quiz
6 Questions
The largest value is -
10
The smallest value is -
1
Calculation to find range -
10 − 1
The range is -
9
Number not used to find range -
4
1, 3, 7, 8, 10 -
9
3, 1, 10, 10, 12 -
11
3, 9, 11, 15, 14 -
12
4, 9, 8, 7, 7, 14, 12, 13 -
10
Exit quiz
6 Questions
The outlier -
23
The range with the outlier -
24
The range without the outlier -
11
The largest data point -
47
Definitely keep -
An outlier of 28 for number of days in a month without rain.
Definitely remove -
A student walked 200 km to the supermarket.
Investigate further -
19 cats had a mass of 4 - 6 kg. Outlier had a mass of 11 kg.