<p>@GMTplus7 - I don’t think percentiles are the right way to think about it. To go from a 550 to a 650 in SAT CR is a 24 percentile gain, while going from 650 to 750 is only 9 percentiles, but the latter is much harder to do. </p>
<p>Many people here have made huge gains by preparing for the exams. If the OP improves his/her test taking skills and builds the base needed for the ACT, getting a 30 is not unreasonable. </p>