I did a dependent t-test for a medical research, it was comparing before and after measurements.

So the dependent t-test should be the right test to use.

The after measurements have a wide range.

And then the client provided me with another piece of information: "it is very normal for the after

measurements to go up to 20. <20 is considered normal, 20-30 prolonged and >30 abnormal".

I am wondering whether this impacts how I should run the paired t-test? Do I need to do some

something extra to include this information to my test?

Thank you in advance.

M