Box-Whisker Plots on TI-89
Copyright © 2015–2023 by Stan Brown, BrownMath.com
Copyright © 2015–2023 by Stan Brown, BrownMath.com
Summary: You can use your TI-89 to create a box-whisker diagram, also known as a boxplot. Boxplots give you a general idea of the shape of the data, particularly its skew, and they highlight outliers in the data set.
Alternatives: If you have a TI-83/84, see Box-Whisker Plots on TI-83/84 or use MATH200A Program part 2.
Let’s make a boxplot of this data set:
11 | 15 | 14 | 12 | 9 | 8 | 7 | 5 | 6 | 11 |
10 | 10.5 | 12 | 11 | 13 | 2 | 6 | 4 | 13.5 | 22 |
Get into the Stats/List Editor. | [◆ ] [APPS ], select Stats/List Editor, and you
should be on the list entry screen. |
Enter the data points. | ![]() list1 (not the first data
line) and press [CLEAR ] [ENTER ] to clear the list.
Enter the x values. (The order doesn’t matter.) |
Disable any other plots and graphs that could overlay your box-whisker plot | [F2 ] [3 ] turns off statistics plots, and [F2 ] [4 ]
turns off graphs of equations. |
Get to the Plot Setup screen, and select a modified boxplot. (“Modified” means it shows outliers if there are any.) | ![]() F2 ] [1 ]. Then, cursor to an empty plot, or one you
don’t care about keeping.
Press [ F1 ] [► ] [5 ]. |
Fill in the Define Plot screen. | ![]() ALPHA ] key to type list1 :
[ALPHA 4 makes l ] [ALPHA 9 makes i ] [ALPHA 3 makes s ], then plain
[T ] [1 ] [ENTER ] [ENTER ]. |
On the box-whisker diagram, any outliers show as isolated squares. The whiskers are mix and max (disregarding any outliers), and the box is first quartile, median, and third quartile. | ![]() F5 ], which is ZoomData or “zoom to
statistics data”. |
Identify the outliers, if any. | ![]() F3 ] to trace on the plot. Use [◄ ] and
[► ] to display the numbers in the five-number
summary as well as any outliers. Here, you see that there is an
outlier with a value of 22. |
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