Box-Whisker Plots on TI-83/84

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.

Let’s make a boxplot of this data set:

Step 1: Enter the numbers in L1.

Enter the data points.

[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.

	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.	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.	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.	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.	Press [ZOOM] [9], which is ZoomStat or “zoom to statistics”.
	Press [TRACE]. Use [◄] and [►] to display the numbers in the five-number summary as well as any outliers.