TC3 → Stan Brown → TI-83/84/89 → Box-Whisker
revised 18 Dec 2012

Box-Whisker Plots on TI-83/84

Copyright © 2012–2014 by Stan Brown, Oak Road Systems

Summary: You can use your TI-83/84 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.

Alternative: MATH200A Program part 2 sets up the plot automatically for you.

Let’s make a boxplot of this data set:

11151412 9875 611
1010.5 1211132 6413.522

Step 1: Enter the numbers in L1.

Enter the data points. data points entered in L1 [STAT] [1] selects the list-edit screen.
 
Cursor onto the label L1 at top of first column, then [CLEAR] [ENTER] erases the list.
 
Enter the x values. (The order doesn’t matter.)

Step 2: Clear other plots.

In this step, you disable any other plots and graphs that could overlay your box-whisker plot.

sample Y= screen Press [Y=] to open the list of equations and plots.
Look at the plots across the top, and look at the column of = signs. If any are enabled (highlighted), disable them. Y= with highlights removed Use the arrow keys to get to any highlight, and press [ENTER] to remove the highlight.
 
Caution! There are ten equations. Use [] to scroll down and check them all, down to Y0.

Step 3: Set up the boxplot.

Clear the grid and enable coordinate display for later use in tracing. Format screen with GridOff Press [2nd ZOOM makes FORMAT].
 
If GridOn is highlighted, press [ 3 times] [ENTER].
 
If CoordOff is highlighted, use the [] or [] key to get to CoordOn, and press [ENTER].
Select Plot1. Press [2nd Y= makes STAT PLOT] [ENTER].
Select the modified box-whisker plot. Press [] [ 3 times] [ENTER] []. The bottom part of the screen may change when you do this.
Select list 1, frequency 1, and squares for outliers. Plot1 setup screen Press [2nd 1 makes L1] [ENTER].
 
Freq is probably already set to 1. If it is, press [ENTER]. If it’s not 1, press [ALPHA] [1] [ENTER].

Step 4: Display the boxplot.

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. boxplot Press [ZOOM] [9], which is ZoomStat or “zoom to statistics”.
trace showing numerical value of outlier Press [TRACE]. Use [] and [] to display the numbers in the five-number summary as well as any outliers.

This page is used in instruction at Tompkins Cortland Community College in Dryden, New York; it’s not an official statement of the College. Please visit www.tc3.edu/instruct/sbrown/ to report errors or ask to copy it.

For updates and new info, go to http://www.tc3.edu/instruct/sbrown/ti83/