Publics are often significantly more lenient with instate that OOS stats. In fact, UNC does break down the stats between IS and OOS, and it also appears the stat you have is out of date. For the entering class this year, the 75th percentile for instate is 1500, and the 75th percentile for OOS is 1540. That puts you in the middle 50, not “way above” the 75th percentile. https://admissions.unc.edu/files/2020/10/Class-Profile-2020_FINAL.pdf Furthermore it’s possible, as with many other schools just below the top 10-20, that the admit middle 50 is a little higher than the entering middle 50.