JMP Tutorial:
Areas to the Left of a Point Under the Normal Curve

We are goind to do examples 1.17, 1.18 and 1.19 on pages 60 and 61 and some similar problems.
In particular, we are going to find the areas to the left of several points under normal curves with different means and standard deviations.

Open a new JMP data table:

Click on top of the column to highlight it and type "mu" to name this column:

Double click on the dark dot to create a new column. While the column is still highlighted type "sigma" to name it:

Create another column and name it "x":

Enter the values of mu, sigma, and x used in Example 1.17:

Let's enter several more values not in this example as follows:

Create another column and name it "z":

Right click on top of the z column and select Formula... from the pop up menu:

This should bring you to the JMP calculator:

Do the following

• Click on the x column
• Click on the minus (-) button
• Click on the mu column
• Select x - mu so that is has a red box around it:

• Click on the division button
• Click on the sigma column:

Click OK:

Compare the result of the first two rows with those in Example 1.17.

To find the area to the left of these z values, create another column in JMP. Call it Probability. Go to the calculator for this column as was done for the z column:

Select Normal Distribution from the Probability group of functions:

Click on the z column:

Click OK:

Compare the answer in the first row with that in Example 1.19.

The file that was created for this problem can be downloaded here.