Stats Test and interval tool (TI-Interactive!) By John Beach

I have discovered that Normal graphs can be easily created on TI-Interactive!

Use the Insert “Stat Tests and Intervals tool…” or click on the icon on the toolbar.

Set the following parameters.

• check Summary Statistics
• μ_o = 0
• σ = 1
• n = 1
• check Draw Result

• Set = z-score you wish to shade from
• Select the correct Alternate Hypothesis. These correspond to P(z £ a or z ³ a), P(z £ a), and P(z ³ a)

Click on “Calculate”. The graph will be displayed. Both the colour of the line and shading can be changed.

Press “Functions” button on the Graph window. Then press the line type on the Functions window.

Click on the two color boxes and set them to the desired color. I usually choose black for the line and grey for the Shade.

Click “OK” to close the Graph styles box

Click “Format” button on the Graph window. Select the Labels tab and deselect Axis Labels.

Select the Axes tab and Select “Show Tick Mark Values”

Select the Font size of the Horizontal Axis at this time by pressing the Font… Button. Press “ OK” to close the Format window.

Maximize the Graph window to easily add more text or fine tune the window. I usually add a zero and set the minimum value below the graph to –0.1 to give more room for labels and text.

Press the save and close button , adjust the size of your graph in
TI-Interactive and copy and paste to your document.

Various effects can be created by using the Alternate Hypothesis choices.

Creating an area between two z-scores

eg. P(–1 £ z £ 1.4)

Use Summary Stats, m = 0, s = 1, n = 1, = 1.4. Calculate the results. Then immediately select the “Tests and Intervals Setup” tab on the Statistics Tests and Intervals window. Change to –1. Calculate again. The graph window will have both together.

Select the Format button. And change the following colours.

• First graph colour is to be grey
• Second graph is to have a black line but shading under the curve is set to white

The final results can be great.

Creating various graphs with Y1 =

Graph using the basic graphing function is TI-Interative!

Y₁= normalpdf(x)

Y₂= normalpdf(x,1.3,1.5)

NOTE: When creating more than one final graph it is best to start over from the beginning and delete all windows and graphs in
TI-Interactive! to that point. The “Stat Tests and Intervals tool…” has an accumulative effect. So this resets everything to a fresh start.