7th Grade Math

506 Statistical Displays

Double Box-and-Whisker

Plots

The double box-and-whisker plot below shows the daily

attendance of two fitness clubs. Compare and contrast the range

and variance of the attendance at Super Fit versus Athletic Club.

45 50 55 60 65 70 75 80 85 90 95 100 105 110

• Athletic Club

Super Fit

Super Fit had an attendance between 48 and 82. The Athletic Club

had an attendance between 57 and 110. The attendance at the

Athletic Club varies more than the attendance at Super Fit.

c. SPORTS The number of games won in each conference of the

National Football League is displayed below. Compare and

contrast the range and variance of each conference.

123 45678910111213

/BUJPOBM
'PPUCBMM
-FBHVF
8JOT

American Football

Conference

National Football

Conference

Examples 1–3 1. EARTH SCIENCE Use the table. Depth of Recent Earthquakes (km)

5 15 1 11 2 7 3

9 54 9105 7

a. Make a box-and-whisker plot of

the data.

b. What percent of the earthquakes

were between 4 and 9 kilometers deep?

c. Write a sentence explaining what the length of the box-and-whisker

plot means.

Example 4 2. GAS MILEAGE Use the box-and-whisker plots shown.

15 17 19 21 23 25 27 29 31 33 35 37 39 41 43

Average Gas Mileage for Various Sedans and SUVs

SUVs

Sedans

a. Which types of vehicles tend to be less fuel-efficient?

b. Compare the most fuel-efficient SUV to the least fuel-efficient sedan.

Outliers Outliers If the data set

includes outliers, then the

whiskers will not extend to

the outliers, just to the

previous data point.

Outliers are represented

with an asterisk (*) on the

box-and-whisker plot.

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