Your example is an Allegheny Institute fantasy, though - Pittsburgh isn’t spending double per student. They are spending lots on a large number of disadvantaged students.

I’m not going to get mad about imaginary numbers. You can’t fairly compare a large school district with lots of special needs/disadvantaged kids vs a rich, white suburban school by just dividing by the number of students. Some students cost vastly more to educate - those are much, much rarer in the suburbs.

Trying to boil it down to a percentage is just one problem with your approach. You’re looking at Pittsburgh’s needs vs rich suburbs and not considering ANY of the structural differences between who those districts serve and what they do.

All in the name of cutting money for education - something we definitely don’t need.

The magic number is whatever it takes to give EVERY student a quality education.