Math 160 - TI Calculator Handout #1
Math 160 - CooleyTI Calculator Handout #1 OCC
Histograms on the TI-84+ Calculator
Example: Consider the data, 1, 1, 2, 3, 3, 3, 4, 5, 5, 6, 7, 7, 7, 7, 7, 7, 7, 9, 9, 10. Construct a frequency histogram for the data.In order to answer this question, we must do the following:
Part 1: Entering The Data As A List
- The data must be stored in the calculator as a separate list, before any calculations can be made.
1)Press STAT. The cursor should already be on EDITand 1:Edit…. So, press ENTER.
2)At this point you should see 3 columns labeled L1, L2, and L3. If there are data present you must clear all the entries. To do so you can simply cursor over the unwanted entries and press DEL each time. However, if you would like to delete the entire list cursor over the list name (L1) at the top and press CLEARENTER. Do not pressthe DEL button! In the event that L1 was deleted or was simply not present, you must position the cursor
across the top where you want L1to go. Press 2NDINS . Then, press2NDL1. This will insert L1back in the
column where it originally belonged. Now, let’s enter the data in column L1. You can pressENTER or cursor down eachtime until all entries are entered. When you are finished, your screen should look exactly like
Figure 1 below.
Figure 1
Part 2: Turning On Stat Plot
- After the data is stored in the calculator, we must set up our Stat Plot options in order to display a histogram.
1)Press 2NDSTAT PLOT. There are 4 different categories for Stat Plot options. We will simply use the first one. The cursor should already be on STAT PLOTSand 1:Plot1...,so justpress ENTER.
2)On this menu, there are six different attributes that must be set:
a) The top line should read Plot1 Plot2 Plot3. Make sure that Plot1 is highlighted. If Plot1 is not
highlighted, cursor over Plot 1 and press ENTER.
b) The second line reads On Off. This is where we tell the calculator to turn on the Stat Plot for Plot1. Make sure that On is highlighted. Just cursor over and press ENTER to highlight the On option. c) Cursor down one line.
The cursor should already be located on the first graphic of the line for the
Type:option. The first graphic is thescatterplot feature.Cursor over two places
to the third graphic which is the histogram. Press ENTER.
d) Cursor down one line to the Xlist: option and make sure it reads L1. If it does not, press2NDL1.
e) Cursor down one line to the Freq: option and make sure it reads 1. If it does not, press 1.
See Figure 2 to verify the above settings. Keep in mind, once all of these options have been selected, you need not to go back each time and repeat the above process. However, it is always a good idea just to make sure that all the options stay the same.
Figure 2
Part 3: Displaying The Histogram
- When Parts 1 and 2 are completed, we can finally graph/display a histogram.
1)Press ZOOM then go to 9:ZoomStat.The histogram will now be displayed in the window. See Figure 3.
However, since the ZoomStat feature is similar to a ZoomFit for regular graphing of functions, the calculator
generates its own class width size.
Figure 3
Part 4: Displaying The Generated Class Limits
- While the histogram is displayed, we can find and identify the class limits it was calculated at.
1)Press TRACE. The class limits for the first column is now displayed. See Figure 4.
From here, we see that the first class is (1 2.8), with a frequency of 3, and the class width is 1.8.
2)Cursor over to the right, and the second column has the limits of (2.8 4.6) with a frequency of 4. See Figure 5.
3)Continue to cursor over to get the rest of the class limits.
Figure 4 Figure 5
Part 5: Changing The Class width
If you want to change the class width, simply do the following:
1)PressWINDOW.Because of the ZoomStat feature, the scales for x-axis and y-axis have been adjusted to fit
and accommodate the entire histogram on the window.
2)Cursor down to Xscl.This feature normally plots the tick marks on the axes of a rectangular grid. For a
histogram, it is alternately used for class width. Enter 1 for the class width (which is single value grouping).
3)PressGRAPH. The result is shown in Figure 6.
Figure 6
Sample TI Calculator Quiz on Histograms
Example: A teacher asked each of her 29 students how many novels they had read in the previous six months. The
results are shown below.
0, 1, 5, 4, 2, 1, 3, 2, 2, 7, 2, 5, 0, 1, 0, 1, 1, 2, 6, 0, 2, 3, 1, 2, 0, 2, 1, 1,9
Construct a frequency histogram for the test scores on your TI-calculator. Sketch the window exactly as it appears on your TI-calculator when using ZoomStat. Write your answer in the box provided to the right. Also include the first three classes that were generated by the TI-calculator.
Solution:
(0 1.5) (1.5 3) (3 4.5)
1