COURSE 3 LESSON 10-4
Box-and-Whisker Plots
Make a box-and-whisker plot for this data on study
hours per week: 10, 13, 16, 17, 20, 22, 23, 24, 26, 30, 31.
Step 1 The data is in order from least to greatest. Find the median.
10 13 16 17 20 22 23 24 26 30 31
The median is the sixth number, 22.
Step 2 Find the lower quartile and the upper quartile. They are the
medians of the lower and upper halves.
10 13 16 17 20 22 23 24 26 30 31
The lower quartile is 16, and the upper quartile is 26.
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COURSE 3 LESSON 10-4
Box-and-Whisker Plots
(continued)
Step 3 Draw a number line that spans all of the data values.
Mark points below the number line at the least and greatest values, at
the median, and at the lower and upper quartiles.
Use the lower and upper quartiles to form a box. Mark the median.
Then draw whiskers from the box to the least and greatest values.
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COURSE 3 LESSON 10-4
Box-and-Whisker Plots
Write a paragraph to compare the data shown in
these plots.
The median attendance for football, around 1,750, is over four times
the median for soccer, 400.
The range for soccer is 2,600, which is larger than the range for football.
Attendance for football is more tightly grouped around the median than
for soccer.
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COURSE 3 LESSON 10-4
Box-and-Whisker Plots
1. Describe the following box-and-whisker plot.
lower quartile is 8,
upper quartile is 14,
median is 10,
whiskers extend to 6 and 18
2. Make box-and-whisker plots on a single number line to compare the
individual points scored by boys and girls.
Girls: 14, 15, 18, 20, 21, 21, 24, 24, 25, 27, 29
Boys: 8, 8, 9, 10, 14, 18, 25, 25, 28, 28, 30
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