these numbers:
20,17,21,15,16,15,12,14,15,19,21,17,20,22,16,
19,21,13,22,14,15,18,20,13,18,16,15,19
the mean is 17.25
the range is 10
what would you give as the pass mark?
This would vary depending on what type of a test it was and the leniency of the teacher. It should be below the mean, but how far depends on what proportion you would fail.
You are giving the passing grades.