Statistical Analysis Graphic calculator page

Graphic Calculator method:

 

Entering sample Data:

One variable:

• Press. 

• Press (you should see 1:Edit on the screen).  You should see 3 columns: L1, L2, L3. 

• The cursor should be at L1 (if not, arrow over to it). 

 

 

• Type in the first number, then . 

• Type in the second number, then . 

• When finished, press The mode button is to the right of the 2^nd button. The text 'Quit' is written above the MODE button.

 

Two Variable data entry:

• Begin as above but when you reach the end of the L1 data list

• Press .  The cursor should jump to the top of the second column, L2. 

• Enter the  y-values (make sure they line up with the corresponding x values in L1). 

• When finished, press

 

 

Descriptive Statistics.

• Press .  Use the blue to move the highlighted bar over the CALC menu. 

• Choose the 1-Var stats option (that is, press ). 

 

 

• You'll see the words 1-Var Stats on the screen. 

• Press (you should see L1 above the key).  You'll see the words 1-Var Stats L1 on the screen.

•   Press .   

 

Mean:

• The mean is the top value on the screen.

Standard Deviation:

•   The sample standard deviation is the fourth value on the screen. 

Correlation.

The TI-83 will only display the correlation in the DiagnosticOn mode. 

• press   (you should see the word CATALOG above the key).  You'll see a screen with an alphabetical list of commands. 

• Arrow down to DiagnosticOn.  Press .  The screen will now say DiagnosticOn. 

• Press again. 

  • You will see the word Done

You can continue now. 

• Press .   Use the blue to move the highlighted bar over the CALC menu. 

• Choose the LinReg(a+bx) option (that is, press ). You'll see the words LinReg(a+bx) on the screen. 

 

 

 

 

• Press (you should see L1 above the key), then  (you should see L2 above the key).  You'll see the words LinReg(a+bx) L1,L2 on the screen. 

 

 

 

 

• Press .  The correlation is the fourth number in the list (r = ..). 

• [NOTE: You can also find correlation by pressing 4: LinReg(ax+b), instead of 8: LinReg(a+bx). 

• In this case, the roles of the a and b are switched, but r is the same.]

 

TTEST comparison of the means of two samples.

Images are based on the print output by the Virtual TI 83.

t-Test for two samples, unpaired data, two-tailed test, population mean unknown.

1. Press ON ( button 1 in the diagram)

2. Press STAT (button 2 in the diagram)

3. You will see this screen

L1 is going to be the list of the first sample of data

• L2 will be the list of the second sample of data

• we don't need a third list but if necessary it there for you to use.

 

4. Add the data using the calculator keypad after every data point Press ENTER (button 4 on the diagram)

• Once you have all the data in sample 1 move to L2

• To do this use the arrow key pointing right (button 3) on the main calculator image to the left.

 

 

 

5. When you have finished entering your second set of data your screen will look something like this one:

• If you make a mistake entering data highlight the data point and overwrite the entry.

• If you want to clear the whole list move the cursor to the L1 or L2 at the top of the column and use the CLEAR button ( do not use the delete button which will remove the column itself)..

 

 

6. PRESS STAT and you will see a screen that looks like this one:

Using the arrow keys on the keypad move the cursor to the right from EDIT to TESTS

This will automatically provide you with a list of the statistical tests available.

 

 

7. Scroll down to number 4 using the Keypad arrows

We are scrolling down to select number 4.

2- SampTTest.........

 

 

8. Your screen will now look like this one:

Press ENTER

 

 

 

9. We now have some choices to make about our statistical test:

• DATA will be selected and flashing by fault . Leave this setting.

• leave the setting as seen in the image to the left.

• make sure u1 is selected as shown ( this is the Two tailed selection) and Pooled: Yes

 

10. Scroll down a little more using the arrows on the keypad

• Select Calculate

• Press ENTER

 

 

11. Results:

The calculation is complete.

t =is the value we have been calculating

p= is the probability of the two samples being the same by chance. Here it is p= 2.5 X 10^-4

 

Tables of Critical T values