New
New
Year 11
Higher

Comparing box plots

I can interpret a box plot and compare two box plots.

New
New
Year 11
Higher

Comparing box plots

I can interpret a box plot and compare two box plots.

Lesson details

Key learning points

  1. A box plot allows us to make conclusions about the data set
  2. Box plots can be compared to highlight similarities/differences in data sets
  3. The box part tells us about the middle 50% of the data

Common misconception

Not referring to the context of the question when comparing the data.

Highlight that just saying the median or the middle 50% of data is bigger is of little use unless you know what the data was about. Check that pupils understand the context of the question.

Keywords

  • Box plot - A box plot is a diagram that clearly shows the minimum and maximum value of a data set along with the three quartiles.

  • Median - The median is the central (middle) piece of data when the data are in numerical order. It is a measure of central tendency representing the average of the values.

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

Collect data from the class, split into groups and compare the data by drawing box plots. For example, pupils could collect data on how many seconds they can hold their breath for. Alternatively, this is an opportunity to use data from other subjects, such as Geography or Science.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
The vertical line inside the box of a box plot represents the .
Correct Answer: median
Q2.
What is the height of the tallest person?
An image in a quiz
Correct Answer: 146 cm, 146cm, 146
Q3.
What is the lower quartile height?
An image in a quiz
Correct Answer: 115 cm, 115
Q4.
What is the upper quartile of this set of data? 17, 13, 19, 21, 13, 14.
Correct Answer: 19
Q5.
Below is the box plot for this set of data: 17, 13, 19, 21, 13, 14. What is the value of point A on the box plot?
An image in a quiz
Correct Answer: 13
Q6.
Below is the box plot for this set of data: 17, 13, 19, 21, 13, 14. What is the value of point D on the box plot?
An image in a quiz
Correct Answer: 19

6 Questions

Q1.
Anything below the __________ represents 25% of the data.
lowest value
Correct answer: lower quartile
median
upper quartile
highest value
Q2.
Anything below the upper quartile represents what percentage of the data?
Correct Answer: 75%, 75
Q3.
What is the range of the middle 50% of data?
An image in a quiz
Correct Answer: 16 cm, 16cm, 16
Q4.
A box indicates data that is more consistent.
Correct Answer: narrower, smaller
Q5.
Which class did better on average?
An image in a quiz
Correct Answer: B, b
Q6.
Which class has more consistent scores?
An image in a quiz
Correct Answer: A, a