JMP Tutorial:
Two Sample t Test (assuming unequal population variances)

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

• Product Effectiveness

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 μ₁ - μ₂ (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)