Corrected entry: At the end of the movie, the boys wonder if Chris will acknowledge them in High School since she is a Senior(4th yr) and they are Freshman(1st yr). Earlier in the movie, the kids ages were established as 15 for the boys and 17 for Chris. So they should be 2yrs apart in school, not 3yrs.
Phixius
24th May 2011
Adventures in Babysitting (1987)
Correction: He could have also stayed back a year.
Correction: Depends on when their birthdays are. My son was a year older, numerically, than everyone else in his class because his birthday is at the end of the summer, just before the school year starts. 15 year olds could be three grades behind a 17 year old for this (or the opposite) reason, among others.
Phixius ★