Post on 28-Mar-2015
Box and whisker diagrams
A box and whisker diagram
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Click on the loudspeaker symbol in the title box of this slide to hear the commentary..
A box and whisker diagram
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Click on the loudspeaker symbol in the title box of this slide to hear the commentary.
25% of data 25% of data 25% of data 25% of data
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A set of test results in a box and whisker diagram
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Click on the loudspeaker symbol in the title box of this slide to hear the commentary.
The terminology!
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upper quartile
medianlowerquartil
e
lower extrem
e
upper extrem
e
The five points on a box and whisker plot gives you the upper & lower extreme values (numbers) of the data (the range or spread of the data), the upper & lower quartiles (the interquartile range or spread of the middle 50% of the data) and the median (centre point of the data).(Click on the loudspeaker symbol in the title box of this slide if you want to hear the commentary. Then listen to the recap on the next slide).
Video 01…….0.28 – 1.27
Click on the image below to play the video
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Quick ‘recap’ questions:
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1. What is the range of the test data?2. Give the median mark for the test.3. What is the interquartile range of the marks?Answers on next slide.
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A set of test results in a box and whisker diagram: some initial questions
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1. What is the range of the test data? Ans: 120 – 30 = 90
2. Give the median mark for the test. Ans: 603. What is the interquartile range of the marks?.
Ans: 85 - 40 = 45 (the range of the middle 50% of the class.)
Click on the image below to play the video
Question on range of data:
A box and whisker plot appears below.
Work out the range of the data shown below:
Click on the image below to play the video
Answer:
A box and whisker plot appears below.
The range of the data is:
Answer: 83
(Not 17-100 although that is a common mistake.
The range is a single number so taking the highest value, subtract the lowest value. In this case 100 – 17 = 83.)
Click on the image below to play the video
A box & whisker question: median
The box & whisker chart opposite shows absence data for five year groups in term one.
Which year group had the smallest median number of absences?
Absence data for term 1
Num
ber
of
abse
nce
s
Click on the image below to play the video
Answer:
The box & whisker chart opposite shows absence data for five year groups in term 1.
Which year group had the smallest median number of absences?
Click on the image below to play the video
A box & whisker question on range:
The box & whisker chart opposite shows attendance data for five year groups in term one.
Which year group had the smallest interquartile range of absences?
Absence data for term 1
Num
ber
of
abse
nce
s
Click on the image below to play the video
Answer:
The box & whisker chart opposite shows attendance data for five year groups in term one.
Which year group had the smallest interquartile range of absences?
Click on the image below to play the video
Another box & whisker question:
The box & whisker chart opposite shows attendance data for five year groups in term one.
Which year group had half of its members recording 6 or more absences?
Absence data for term 1
Num
ber
of
abse
nce
s
Click on the image below to play the video
Answer:
The box & whisker chart opposite shows attendance data for five year groups in term one.
Which year group had half of its members recording 6 or more absences?
Click on the image below to play the video
Another box & whisker question:
The box & whisker chart opposite shows attendance data for five year groups in term one.
Which year group had over three quarters of its members recording 6 or more absences?
Absence data for term 1
Num
ber
of
abse
nce
s
Click on the image below to play the video
Answer:
The box & whisker chart opposite shows attendance data for five year groups in term one.
Which year group had over three quarters of its members recording 6 or more absences?
Thank you
For further sources of support and practice on box and whisker diagrams, look at the next slides.
http://www.bbc.co.uk/schools/gcsebitesize/maths/statistics/representingdata3hirev6.shtml
http://www.education.gov.uk/schools/careers/traininganddevelopment/professional/b00211213/numeracy/areas/box-and-whiskers
https://www.khanacademy.org/math/probability/descriptive-statistics/Box-and-whisker%20plots/v/reading-box-and-whisker-plots
http://www.youtube.com/watch?v=QXp596gfG3c
Need things explained again?
http://www.brainingcamp.com/resources/math/box-plots/questions.php
http://www.jmap.org/JMAP/RegentsExamsandQuestions/PDF/WorksheetsByPI-Topic/IntegratedAlgebra/Statistics_and_Probability/A.S.6.BoxandWhiskerPlots1.pdf
http://studentzone.roehampton.ac.uk/howtostudy/onlinemathsmaterials/downloadableworksheets/tdamaths/bw&cumulative.pdf
Box and Whisker worksheet – Word document to download
Want to practise?
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Good luck!
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