My wife was school superintendent for two school districts in Marin County (San Rafael). Granted it was a very wealthy area but the parents were super involved in all aspects of their child's education. Additionally these parents were able to afford many, many fund raising events including several "casino nights" many of which I attended during the 4 years she was head of the two districts. All of the money went directly into school supplies, services, and other things that benefited the students.
Barb was also deputy superintended down here at Capistrano Unified School District which draws from a huge income differential yet has the same parental involvement as up in Marin County. Then again I know that many of the inner city schools in L.A. have little parental involvement some of which seems obvious to most.