A Quant score of 48 currently represents the 76th percentile. A Quant score of 47 is the 70th percentile and a 49 is the 81st percentile. So within the space of 3 increments of the scaled score 11 percentiles are captured.

Logic will tell you that someone has to be able to be in the 78th percentile, right? And the 79th percentile as well? A 78th percentile score will likely be represented as a scaled score of 48 since it is closest to that 76th percentile number. A 79th percentile likely will be reported as a scaled score 49 since it is closer to that 81st percentile number.

So you see that there are "high scaled score 48s" and "low scaled score 48s" representing percentiles that may differ by 3 or 4 percentiles, from around the 74th to the 78th.

The verbal score has much less variation since the scaled score is a much more precise at the high end of the verbal section. A verbal 37 is the 82nd percentile and since a 36 is the 80th and a 38 is the 84, a 37 will always be pretty close to an 82nd percentile, from 81 to 83, presumably.

This variability in percentiles represented by the same scaled score, particularly seen in the higher Quant scores, can lead to different over numbers with the same scaled scores.

This is why as Rich says, scores could vary by 10 points in either direction. The same scaled score numbers might literally represent different percentiles.

Does that help?

For further information (and a confused sort of reply from GMAC!) you can read this thread: https://www.beatthegmat.com/percentile-a ... 16598.html