Dot Plot

This page is devoted to presenting, in a step by step fashion, the keystrokes and the screen images for doing a generating a Dot Plot on a TI-83 (TI-83 Plus, or TI-84 Plus) calculator.

We will generate a list of data on the calculator, using GNRND4 with Key 1=413728702 and Key 2=4100325. That list will be the same numbers that appear in the following table: Thus, our problem will be to generate a dot plot diagram for the data in the list above.

Figure 1 We start with a run of the GNRND4 program, giving the program the specified key values. Press to continue.

Figure 2 After skipping over two intermediate screens, the program displays the generated values. These are the same as the values shown above. The program saves these values in the list L₁. Again, press to finish the program.

Figure 3 We return to the list of programs via the key. Then use teh key to move the highlight down to the DOTPLOT program. Press to select that choice.

Figure 4 The command prgmDOTPLOT is pasted on the main screen. Press to perform that command, i.e., run the program.

Figure 5 The program starts with information about itself, and then it asks for the location of the data to use. We respond with to indicate that the data is in L₁. Then press to continue the program.

Figure 6 The DOTPLOT program does some more computations and then it finally displays the dot plot as shown in Figure 6.
Although the plot is accurate, it is a bit confusing in that we have no idea, from the plot, about the values being represented. One way to try to find out some of those values is to move into Trace mode. Press the key to move to Figure 7.

Figure 7 Now we are in trace mode. The claculator has highlighted (although it is almost impossible to see this) the first point being plotted. Furthermore, the calculator is displaying the cooordinates of that point, namely (325,1). The highlighted point is in the lower left corner of the plot. The highlight amounts to four little dots surrounding the point. Here is a magnification of the lower left corner with those dots displayed in red.

Figure 8 If we use the key repeatedly we can move that highlight to subsequent points on the plot. In Figure 8 we have moved to highlight the eleventh point, the one at the top of the first column. Its coordinates are (324,11).

Figure 9 Using one more time moves the highlight to the twelfth point, the lowest one in the second column. Its coordinate is (326,1).

Figure 10 We can exit the plot by using the sequence . This takes us back to the main screen.

Figure 11 We want to see some of the background processing for DOTPLOT. We know that the data was in L₁. We move to the STAT menu via the key. Then press to open the Stat editor show in Figure 12.

Figure 12 It is pretty clear that the DOTPLOT program sorted the values in L₁. We can use the key to move down the list to inspect more values.

Figure 13 To get to Figure 13 we have moved down the list to highlight the 17^th item (Note the L1(17)=327 at the bottom of the screen.) At the top of the list we see the final 325 point. Then there are five 326 values. Then we start the 327 values. However, nothing appears in the other lists being displayed. Were we to look at a listing of the DOTPLOT program, we would find that the program uses L₁ aned L₆. We can move to the right, using the key, to look at L₆.

Figure 14 For Figure 14 not only have we moved to display L₆ but also we have moved down the list to highlight the 17^th item in that list. Thus, Figure 14 parallels Figure 13. In L₆ we are seeing the second coordinate for each of the plotted points.
This would be easier to see if we could display L₁ and L₆ side-by-side. We will cause this to happen.

Figure 15 Use to exit Figure 14 and return to the main screen.

Figure 16 Use to open the STAT menu. From that menu select the fifth option by pressing the key.

Figure 17 That action caused the SetUpEditor command to be pasted onto the main screen.

Figure 18 We will append L₁,L₂ to this via the key sequence . Then press to move to Figure 19.

Figure 19 Here we see that the calculator has told us that it has completed the command. Now return to the STAT menu via the key and move to the editor via the key.

Figure 20 Figure 20 show us the two lists, side-by-side, as we had wanted.

Figure 21 For Figure 21 we have moved down the lists so that we can see the 17^th item at the bottom. Now it is easy to see the correspondence between the values in L₁ and L₆ as being the coordinates of the points plotted on the graph.

Figure 1	We start with a run of the GNRND4 program, giving the program the specified key values. Press to continue.
Figure 2	After skipping over two intermediate screens, the program displays the generated values. These are the same as the values shown above. The program saves these values in the list L₁. Again, press to finish the program.
Figure 3	We return to the list of programs via the key. Then use teh key to move the highlight down to the DOTPLOT program. Press to select that choice.
Figure 4	The command prgmDOTPLOT is pasted on the main screen. Press to perform that command, i.e., run the program.
Figure 5	The program starts with information about itself, and then it asks for the location of the data to use. We respond with to indicate that the data is in L₁. Then press to continue the program.
Figure 6	The DOTPLOT program does some more computations and then it finally displays the dot plot as shown in Figure 6. Although the plot is accurate, it is a bit confusing in that we have no idea, from the plot, about the values being represented. One way to try to find out some of those values is to move into Trace mode. Press the key to move to Figure 7.
Figure 7	Now we are in trace mode. The claculator has highlighted (although it is almost impossible to see this) the first point being plotted. Furthermore, the calculator is displaying the cooordinates of that point, namely (325,1). The highlighted point is in the lower left corner of the plot. The highlight amounts to four little dots surrounding the point. Here is a magnification of the lower left corner with those dots displayed in red.
Figure 8	If we use the key repeatedly we can move that highlight to subsequent points on the plot. In Figure 8 we have moved to highlight the eleventh point, the one at the top of the first column. Its coordinates are (324,11).
Figure 9	Using one more time moves the highlight to the twelfth point, the lowest one in the second column. Its coordinate is (326,1).
Figure 10	We can exit the plot by using the sequence . This takes us back to the main screen.
Figure 11	We want to see some of the background processing for DOTPLOT. We know that the data was in L₁. We move to the STAT menu via the key. Then press to open the Stat editor show in Figure 12.
Figure 12	It is pretty clear that the DOTPLOT program sorted the values in L₁. We can use the key to move down the list to inspect more values.
Figure 13	To get to Figure 13 we have moved down the list to highlight the 17^th item (Note the L1(17)=327 at the bottom of the screen.) At the top of the list we see the final 325 point. Then there are five 326 values. Then we start the 327 values. However, nothing appears in the other lists being displayed. Were we to look at a listing of the DOTPLOT program, we would find that the program uses L₁ aned L₆. We can move to the right, using the key, to look at L₆.
Figure 14	For Figure 14 not only have we moved to display L₆ but also we have moved down the list to highlight the 17^th item in that list. Thus, Figure 14 parallels Figure 13. In L₆ we are seeing the second coordinate for each of the plotted points. This would be easier to see if we could display L₁ and L₆ side-by-side. We will cause this to happen.
Figure 15	Use to exit Figure 14 and return to the main screen.
Figure 16	Use to open the STAT menu. From that menu select the fifth option by pressing the key.
Figure 17	That action caused the SetUpEditor command to be pasted onto the main screen.
Figure 18	We will append L₁,L₂ to this via the key sequence . Then press to move to Figure 19.
Figure 19	Here we see that the calculator has told us that it has completed the command. Now return to the STAT menu via the key and move to the editor via the key.
Figure 20	Figure 20 show us the two lists, side-by-side, as we had wanted.
Figure 21	For Figure 21 we have moved down the lists so that we can see the 17^th item at the bottom. Now it is easy to see the correspondence between the values in L₁ and L₆ as being the coordinates of the points plotted on the graph.