Your hunch is correct. Wealthy areas have a demographic that supports education. When kids have stable homes, with parents who care about them and their education, schools do well.
When kids move three or four times a year, never know if they are going to eat dinner that night, get beaten or ignored at home, have parents on drugs or in and out of jail, it doesn't matter how much money you pour into the schools.
When kids move three or four times a year, never know if they are going to eat dinner that night, get beaten or ignored at home, have parents on drugs or in and out of jail, it doesn't matter how much money you pour into the schools.