Name: _______________________________________
Algebra
Date: _______________________
Box and Whisker Plot
You are starting to think about what costume you are going to wear for Halloween this year. The prices of 8
costumes sold at two different Halloween stores are shown below.
DeVirgilio’s
Tridico’s Trick or
Disguise Shop
Treat Shop
$20
$80
$30
$58
$25
$24
$82
$68
$39
$65
$34
$63
$81
$59
$28
$72
For questions 1-3, use the prices from DeVirgilio’s Disguise Shop only.
1. Order the prices from least to greatest. _________________________________________________
2. What is the median or middle quartile? _______
Lower quartile? ______
Upper quartile? ________
3. Make a box and whisker plot. Be sure to leave room for a second box and whisker plot.
Use your box and whisker plot (not the chart) for DeVirgilio’s Disguise Shop to answer questions 4-8.
4. What percent of the costumes have a price of $60 or greater? _____________
5. What percent of the costumes have a price of $26.50 or greater? _____________
6. What percent of the costumes have a price of $32 or greater? _____________
7. Knowing that there are 8 costumes, how many costumes have a price of $26.50 or less? ____________
8. What is the interquartile range? ____________________________
For questions 9-11, use the prices from Tridico’s Trick or Treat Shop only.
9. Order the prices from least to greatest. _________________________________________________
10. What is the median or middle quartile ? _______
Lower quartile? ______
Upper quartile? ________
11. Make a box and whisker plot above the plot for DeVirgilio’s Disguise Shop.
Use your box and whisker plot (not the chart) for Tridico’s Trick or Treat Shop to answer questions 12-14.
12. What percent of the costumes have a price of $64 or less? ___________________
13. Knowing that there are 8 costumes, how many costumes have a price of $58.50 or greater? _________
14. What is range of the middle 50% of the data? ______________
Use both box and whisker plots and use the table to answer the following questions.
15. Look at the boxes (middle 50%) of both plots and the interquartile ranges for both shops. How do the
interquartile ranges impact the shape of the box? ________________________________________
16. What does the interquartile range (or shape of the box) tell you about how the data clusters around the
median of both sets of data? _______________________________________________________________
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17. Without calculating the mean, which costume shop do you think will have a mean closer to the median? Why?
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18. Check your prediction by calculating the mean for both shops.
19. Looking at the table, which costume shop has an outlier and what is the outlier?
______________________________________________________________________________________
20. Looking at the box and whisker plots, would you be able to definitively tell if there was an outlier in either set
of data? Why or why not?
______________________________________________________________________________________
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21. Looking at a box and whisker plot, why can’t you be sure that the median and quartiles are actual values from
the data set?
______________________________________________________________________________________
21. Using the information from the box and whisker plots, how do the costume prices from Tridico’s Trick or Treat
Shop compare to the costume prices of DeVirgilio Disguise Shop?
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