How to Construct a Box Plot on the TI-84 Plus
You can use the TI-84 Plus to create a box plot. A box plot consists of a box-with-whiskers. The box represents the data existing between the first and third quartiles. The box is divided into two parts, with the division line defined by the median of the data. The whiskers represent the locations of the minimum and maximum data points.
To construct a box plot for your data, follow these steps:
Store your data in the calculator.
Your data does not have to appear in the Stat List editor to plot it, but it does have to be in the memory of the calculator.
Turn off any Stat Plots or functions in the Y= editor that you don’t want to be graphed along with your histogram.
To do so, press [Y=] to access the Y= editor. The calculator graphs any highlighted Plots in the first line of this editor. To remove the highlight from a Plot so that it won’t be graphed, use the
keys to place the cursor on the on the Plot and then press [ENTER] to toggle the Plot between highlighted and not highlighted.
The calculator graphs only those functions in the Y= editor defined by a highlighted equal sign. To remove the highlight from an equal sign, use the
keys to place the cursor on the equal sign in the definition of the function, and then press [ENTER] to toggle the equal sign between highlighted and not highlighted.
Press [2nd][Y=] to access the Stat Plots menu and enter the number (1, 2, or 3) of the plot you want to define.
Highlight On or Off.
If On is highlighted, the calculator plots your data. If you want your data to be plotted at a later time, highlight Off. To highlight an option, use the
keys to place the cursor on the option, and then press [ENTER].
to place the cursor on the type of plot you want to create, and then press [ENTER] to highlight it.
enter the name of your data list (Xlist), and press [ENTER].
If your data is stored in one of the default lists L1 through L6, press [2nd], key in the number of the list, and then press [ENTER]. For example, press [2nd] if your data is stored in L1.
If your data is stored in a user-named list, key in the name of the list and press [ENTER] when you’re finished. Notice that the calculator is already in Alpha mode, waiting for the first letter in the name of your list.
Enter the frequency of your data.
If you entered your data without paying attention to duplicate data values, then the frequency is 1. On the other hand, if you did pay attention to duplicate data values, you most likely stored the frequency in another data list. If so, enter the name of that list the same way you entered the Xlist in Step 6.
Press [ZOOM] to plot your data using the ZoomStat command.
ZoomStat finds an appropriate viewing window for plotting your data.
If your data has outliers (data values that are much larger or smaller than the other data values), consider constructing a modified box plot instead of a box plot. In a modified box plot, the whiskers represent data in the range defined by 1.5(Q3 – Q1), and the outliers are plotted as points beyond the whiskers. The steps for constructing box plots and modified box plots are the same, except in Step 5 you select the modified box plot symbol.