In this case, it means to invent a comparative measure so that different types of scores can be compared. Fortunately, the statistics wizards have done it already. I like to describe it to persons who never have had statistics as "How far off is it, compared to how far off it's supposed ot be?"
Standard Deviation 20
How far off is it? 81 - 50 = 31
Compare to how far off it is suppsed to be. 31/20 = 1.55
Conclude: Well, then this person is 1.55 "supposed-to-be"s above where the average Joe is.
Standard Deviation 5
How far off is it? 6.4 - 0 = 6.4
Compare to how far off it is suppsed to be. 6.4/5 = 1.28
Conclude: Well, then this person is 1.28 "supposed-to-be"s above where the average Joe is.
That's about it. Compare 1.55 to 1.28 and answer the question.
You may find more technical terms, such as z-score, Normal Deviation, something like that, but I promised that you would have to learn only one word, so I'll leave it at that. There might even be a formula sitting about, somehting like , but again, I don't want to muddy the waters.