Two Sample t Test (assuming unequal population variances)

Click the link below and save the following JMP file to your Desktop:

Now go to your Desktop and double click on the JMP file you just downloaded.

This action will start JMP and display the content of this file:

Notice that **Group** is a categorical variable and **Score** is a
quantitative variable.

Go to the **Analyze** Menu and select **Fit Y by X**:

Click the column **Score** and then click **Y, Response**.

Click the column **Group** and then click **X, Factor**.

You should see:

Click **OK**.

You should see:

Click the red down arrow next to **Oneway Analysis of Score By Group** and
select **t Test**.

The following additional output is displayed:

Prob>|t| = .0264 is the p-value for H_{A}: μ_{T
}- μ_{C} ≠ 0

Prob>t = .0132 is the p-value for H_{A}:
μ_{T }- μ_{C} > 0

Prob<t = .9868 is the p-value for H_{A}:
μ_{T }- μ_{C} < 0

By default, the **Upper CL Dif** and **Lower CL Dif** is the 95%
confidence interval for μ_{1
}- μ_{2}
(Notice the **Confidence 0.95** in the lower left). If you want, for example,
a 98% confidence interval, click the red down arrow next to **Oneway Analysis
of Score By Group** and select **Set α Level**, then **
Other...**:

You should see:

Type 0.02 and click **OK**.

The output now looks like the following:

(Based on JMP Pro 16.0.0 Revised 7/7/2021)