The median-range Composite ACT scores for Penn and Cornell are 30-34 and for Princeton 31-35. If you are a first-generation-to-college applicant and/or come from a disadvantaged or highly unusual background, admission officials will give you some wiggle room when it comes to test scores. The admission officers will also be looking for some other distinctions besides your academic record. Typically, leadership in school organizations doesn’t stand out much at the top universities. 

The majority of successful Ivy applicants submit more than the two required Subject Tests, with most of their scores well into the 700s. You can also re-take your tests if you are not happy with your current scores.