Hi folks,
The GMAC is very explicit that the math sectional raw score and the verbal sectional quant score are not directly comparable. Nonetheless, the percentile breakdowns of the two sections,
here, are very interesting. Note in particular that the highest quant score (51) is only the 97th %ile--a full three percent of the test group gets that score!
Quantitative performance follows a very irregular distribution. That means that many people come in on the bottom, having not used much math in their day-to-day lives for years, but a large group of people (engineers, accountants, etc) are extremely well versed in math and can do exceptionally well on the test.
Conversely, verbal distribution follows a much more typical bell curve with a long tail--scores go up to 51 once again (and once again, not actually directly comparable to a 51 math), but they stop tracking individual percentile at around 45 as the "tail" of the bell curve gets increasingly smaller. Most people, native or non-native, end up in the middle of this range, with very few doing extremely poorly or incredibly well.
For that reason, the "percent below" scores on math and verbal can't really be compared.
Finally, as for the overall scores with that number of errors--as Jonathan said earlier, a lot depends on he location and difficulty of the questions you got wrong, not just the number. The test is adaptive, which means your percent correct is a poor indicator of whether your final number score is accurate. So, take pride in your accomplishments, and use them to build your confidence as you get ready for Test Day!
Best,