Download and open the following JMP data table:

Notice that this table has 800 rows. We are going to select a simple random sample of size fifty without replacement from this large data set.
To do so, go to the Table menu and select Subset:

Fill the resulting dialog box as follows:

Click OK to create the following new JMP data table with the random sample of size 50:
(Don't expect your new random sample data table to look exactly like this one!)