Entering Data As Programs

Instructions for Using the TI-83

Rich Lambert – UNC Charlotte

Entering Data as Programs

1.  Press PRGM. Move the cursor to NEW using the arrow keys.

2.  With the cursor on 1: Create New, press ENTER.

3.  When prompted for the Program Name use the ALPHA key and the green letters to enter the name. It can be up to eight characters in length. Press ENTER when finished entering the name.

4.  The screen should now display the program name at the top and the : symbol on the second line.

5.  Enter data by using the following command syntax. Enter each list on a separate line of program code.

{124,134,125,145}->L1. The STO-> key is used to make the -> symbol. Press ENTER when finished keying in each line of program code.

6.  When finished entering the final list of data, press 2nd QUIT to save the program. You have written your first TI-83 program. All it does in load a dataset into lists. You can also press STAT and then ENTER with the cursor on 1:Edit to enter data directly into lists. These lists can also be named and saved. Lists can be cleared from the active memory of the TI-83 without removing them from the permanent memory by pressing STAT and then ENTER after highlighting 4:Clrlist under EDIT. You will then be prompted to enter the lists you want to clear. For example, Clrlist L1,L2,L3 would clear lists 1-3.

Creating Histograms on the TI-83

1.  Make sure the data you wish to graph is contained in an active list. To verify this, press STAT, then ENTER with the cursor on EDIT and 1:Edit.

2.  Press STAT again.

3.  Use the arrow keys to move the cursor to CALC.

4.  Press ENTER with the cursor on 1-Var Stats. Now press ENTER again.

5.  Descriptive statistics should begin to appear on the screen. Use the arrow keys to reveal all of the values.

6.  In order to produce a histogram you must dimension the graphing window. Press WINDOW.

7.  Set Xmin = no more than the lowest value in the dataset. For the HOTDOG dataset use 105.

8.  Set Xmax = at least as high as the highest value in the dataset. For the HOTDOG dataset use 195.

9.  Set Xscl = the desired class interval width. For the HOTDOG dataset use 10.

10.  Set Ymax = maximum frequency in any interval +1. For the HOTDOG dataset use 6. The remaining settings don’t matter that much. For the HOTDOG dataset we will use these: Ymin=-2, Yscl=1, Xres=1.

11.  Press 2nd STAT PLOT. With the cursor on 1: Plot1 press ENTER.

12.  Select On and the third graph type. The remaining settings should be as follows: Xlist:L1 and Freq:1. Make sure all other Plots are turned Off.

13.  Press GRAPH for the histogram and TRACE to see the values for different positions in the graph appear on the screen. This same process can be repeated for the other two lists by turning Plots On and Off.

Creating Boxplots on the TI-83.

1.  As with Histograms, you must first place the dataset in lists and calculate descriptive statistics. These instructions will assume you have just examined the Histograms for the HOTDOG dataset.

2.  Press WINDOW to change the dimensions of the graphing window. Boxplots are often created for multiple groups of data and displayed together. These instructions will graph simultaneously a boxplot for each type of hotdog. You may also graph histograms and boxplots together for the same list.

3.  Set Xmin = no more than the lowest value in the dataset. For the HOTDOG dataset use 50.

4.  Set Xmax = at least as high as the highest value in the dataset. For the HOTDOG dataset use 250.

5.  The settings for Xscl, Ymin, Ymax, Yscl, and Xres do not matter that much. For the HOTDOG dataset we will use Xscl=10, Ymin=-.05, Ymax=2, Yscl=1, and Xres=1.

6.  Press 2nd STAT PLOT, then ENTER with the on the first plot. For each list, select the 5th type of graph and make sure that the Plot is turned On and set for L1, L2, and L3 respectively.

7.  Press GRAPH for the boxplots and TRACE to see values for different positions in the plots.

Normal Curve Functions

Normalcdf will return the proportion of the area under the normal curve that is under a specified section of the distribution.

1.  Press 2nd DISTR.

2.  Use the arrow keys to highlight 2:normalcdf( , then press ENTER.

3.  Enter the beginning value for the desired region, the ending value, the population mean, and then the population standard deviation. All values must be separated by commas. Close the group of input values with a ). You can use –4 standard deviations units for the lower limit of the distribution and +4 standard deviation units for the upper limit.

4.  For example, normalcdf(500,600,500,100) returns the value of .341345.

InvNorm will return the value in the normal distribution at which a specified proportion of the area under the curve has been reached.

1.  Press 2nd DISTR.

2.  Use the arrow keys to highlight 3:invNorm( , the press ENTER.

3.  Enter the desired proportion, the population mean, and the population standard deviation. All values must be separated by commas. Close the group of input values with a ).

4.  For example, invNorm(.5,0,1) returns the value of 0.0.

Shading Areas Under the Standard Normal Distribution

1.  Press 2nd DISTR.

2.  Use the arrow keys to highlight DRAW, then press ENTER. With the cursor highlighting 1:ShadeNorm( , press ENTER.

3.  Enter the beginning value for the desired region, the ending value, the population mean, and then the population standard deviation. All values must be separated by commas. Close the group of input values with a ). You can use –4 standard deviations units for the lower limit of the distribution and +4 standard deviation units for the upper limit.

4.  Set the dimensions of the graphing window for plotting the standard normal distribution using the following settings: Xmin=-4, Xmax=4, Xscl=1, Ymin=-.2, Ymax=.5, Yscl=0, Xres=1.

5.  For example, ShadeNorm(0,1,0,1) returns the value of .341345, draws the standard normal distribution, and shades the area from z=0 to z=1.

6.  To make multiple plots, you will want to clear the graphing window between plots. You can do so by pressing 2nd DRAW. With the cursor highlighting 1:ClrDraw, press ENTER, and then ENTER again.

Linear Regression

Place the desired data in the STAT editor. Make sure that the independent variable is in L1 and the dependent variable is in L2. Then follow these steps.

1.  Press 2nd CATALOG. Then with the cursor on Diagnostics On, press ENTER, then press ENTER again.

2.  Press STAT. Use the arrow keys to move the cursor to CALC, and press ENTER.

3.  Select 8:LinReg(a+bx) and press ENTER. Now enter L1, L2, and then press VARS. Use the cursor to select Yvars. With the cursor on 1:Function, press ENTER. With the cursor highlighting Y1= (or whatever other unused Y function you want) press ENTER.

4.  Now you should be returned to a screen that says LinReg(a+bx) L1, L2, Y1. Press ENTER.

5.  Your screen should now display the results of the regression analysis.

6.  You may place the residuals in L3 by pressing 2nd STAT. With the cursor placed on 1:RESID press enter. Then press STO->L3 and press ENTER.

7.  You may now plot the scatterplot with the regression equation on it and the residual plot. Select scatterplot for plot1and ask for L1 and L2. Select scatterplot for plot2 and ask for L1 and L3. Press Y= and set Y2=0. Now press ZOOM and select 9:ZoomStat. You should see both plots on the screen.