We don't really know for sure, since the GMAC won't give us a lot of hard numbers. They've given us the following data, which isn't that useful for you, but might be interesting (also, note that it's at least a couple of years old):
- If Student X would normally get a 70th percentile Quant score by answering all 37 questions,
- Then, if Student X took the test in the same way, but instead, ran out of time at the end and had to make 5 random guesses, he'd get a 64th percentile Quant score on average,
- Or if he took the test in the same way, but ran out of time at the end and left five questions
blank, he'd get a 55th percentile Quant score on average.
That doesn't necessarily mean that each blank question is worth a -3 percentile point penalty - the algorithm is much more complicated than that and it definitely depends on how well you were doing up until that point. But that gives you a feel for about the size of the penalty, according to the GMAC.