College Admission for top tier schools for a somewhat average student.

Yes, @austinmshauri is right. They aren’t the same as an IQ tests. There is some correlation and colleges like to see high scores. Scores can be raised with lots of practice. But not all colleges care about testing (students can have test anxiety, or simply have spent more money on prep, amongst other reasons), so OP should consider test-optional colleges too, where her ECs might give her more of a boost.