1. goteachmaths.co.uk Box Plots – Complete Lesson Delete unwanted slides.
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2. 18 November 2018
Box Plots

3. Which class had better results?
Two classes of students took a maths assessment…
…Class A had a median of 65…
…Class B had a median of 67…
…a student in Class B got the highest score…
…two students in Class B also got the lowest scores…
…Class A had a range of 50 marks…
Discussion slide.
…Class B had a range of 40 marks…
Which class had better results?

4. and the upper quartile was 92.
A class of students took a maths assessment…
The lower quartile was 70,
and the upper quartile was 92.
The median score was 78.
The highest score was 102.
The lowest score was 56.
The range was 46.
Highest value
Lowest value
Upper quartile, Q3
Lower quartile, Q1
Median, Q2 50 60 70 80 90
100
110
Assessment Mark

5. A box plot allows us display and then compare data quickly.
Highest value
Lowest value
Upper quartile, Q3
Lower quartile, Q1
No animation.
Median, Q2 50 60 70 80 90
100
110
Assessment Mark

6. Another class took an English assessment…
What is the… highest mark?
What is the… median mark? 84
110
lowest mark?
lower quartile? 70 54
range?
upper quartile? 92 56
Interquartile range? 22 50 60 70 80 90
100
110
Assessment Mark

7. Another class took a biology assessment…
What is the… highest mark?
124
What is the… median mark? 96
lowest mark? 82
lower quartile? 88
range? 42
upper quartile?
114
Interquartile range? 26 70 80 90
100
110
120
130
Assessment Mark

8. Two classes took a maths assessment…
What comments can you make about the
differences between the two classes?
Which class has the… highest mark?
lowest mark?
Both classes got the same median score.
Class A got both the highest, and the lowest, score.
The interquartile ranges are similar, but Class B has a
smaller range which shows they were more consistent.
smallest range?
smallest interquartile range?
Class A
Class B 70 80 90
100
110
120
130
Assessment Mark

9. The noon temperature was recorded for
Blackpool and Brighton over a summer.
Which location had the highest temperature?
Where was the coldest temperature of the summer recorded?
Where would you prefer to go on holiday?
Blackpool had the highest and lowest recorded temperatures,
it also had a higher median temperature than Brighton.
However, Brighton had a smaller range of temperatures and is more consistent,
so it would be a more reliable choice for a holiday.
Blackpool
Brighton 5 10 15 20 25
Temperature (°C)

10. The table below shows data for the salaries of 100 men and 100 women. 3.
The table below shows data for the salaries of 100 men and 100 women.
a) Complete box plots to show this data
b) Comment on the difference between men’s and women’s salaries.
Lowest Salary
Lower
Quartile
Median
Upper
Highest Salary
Men
£6000
£14,500
£21,000
£23,000
£43,000
Women
£5500
£13,000
£19,000
£22,500
£32,000
Children 40 50 60 70 80 1.
Distance (m)
In an experiment, 50 children and 50 adults were given 10 seconds to run as far as possible. The results for the students are shown above.
The slowest adult went 42m, the fastest went 88m. The adults’ median was the same as the students. The lower quartile was 54m and the upper quartile was 74m.
a) Complete a box plot to show the adults’ results.
b) Which group had the furthest and shortest distances?
c) Which group had the smallest range?
5,000
40,000 4.
The table below shows the monthly income for 100 individuals.
Draw a cumulative frequency graph for this data.
Use your graph to estimate the median, as well as Q1 and Q2.
The lowest income was £1250, the highest income was 1750.
Complete a box plot to show this data.
Handout to print.
Class B 70 80 90
100
110 2.
Distance (m)
Two classes took the same physics assessment.
Class A scored a median of 90, a lower-quartile of 80 and an interquartile range of 22. The highest score was 108 and the lowest was 66.
a) Complete a box plot for Class A and compare the data.
Income
Frequency 8 22 32 17 14 5

11. Adults 3.
The table below shows data for the salaries of 100 men and 100 women.
a) Complete box plots to show this data
b) Comment on the difference between men’s and women’s salaries.
b) Men have a higher range of salaries and a higher median. Although both sexes have similar interquartile range, the data indicated men are paid better than women.
Lowest Salary
Lower
Quartile
Median
Upper
Highest Salary
Men
£6000
£14,500
£21,000
£23,000
£43,000
Women
£5500
£13,000
£19,000
£22,500
£32,000
Children 40 50 60 70 80 1.
Distance (m)
In an experiment, 50 children and 50 adults were given 10 seconds to run as far as possible. The results for the students are shown above.
The slowest adult went 42m, the fastest went 88m. The adults’ median was the same as the students. The lower quartile was 54m and the upper quartile was 74m.
a) Complete a box plot to show the adults’ results.
b) Which group had the furthest and shortest distances?
c) Which group had the smallest range?
b) Adults were both faster and slower.
c) Children had a smaller range of distances.
Men
Answers
Women
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
Salary (£)
Class A 4.
The table below shows the monthly income for 100 individuals.
Draw a cumulative frequency graph for this data.
Use your graph to estimate the median, as well as Q1 and Q2.
The lowest income was £1250, the highest income was 1750.
Complete a box plot to show this data.
Answers
Class B 70 80 90
100
110
a) Class A had a wider range and the lowest score. Class B had the highest score, a smaller interquartile range and a higher median.
Class B scored higher and were also more consistent. 2.
Distance (m)
Two classes took the same physics assessment.
Class A scored a median of 90, a lower-quartile of 80 and an interquartile range of 22. The highest score was 108 and the lowest was 66.
a) Complete a box plot for Class A and compare the data.
Income
Frequency 8 22 32 19 14 5

12. Answers x x x x x x Median Estimate = £1460 Q1 Estimate = £13804.
100 x
The table below shows the monthly income for 100 individuals.
Draw a cumulative frequency graph for this data.
Use your graph to estimate the median, as well as Q1 and Q2.
The lowest income was £1250, the highest income was 1750.
Complete a box plot to show this data. x 80 x 60
Income
Frequency 8 22 32 19 14 5 40 x 20
Answers x
1200
1400
1600
1800
Income (£)
Median Estimate = £1460
Q1 Estimate = £1380
Q3 Estimate = £1560
Children
1200
1300
1400
1500
1600
1700
1800
Income (£)

13. Check your success! I can read box plots.
I can draw box plots and compare
data sets using them.
I can create box plots alongside cumulative frequency data.

14. Check your success! I can read box plots.
I can draw box plots and compare
data sets using them.
I can create box plots alongside cumulative frequency data.
Optional
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