Schools are typically funded county by county, with state and federal aid larded on top of that. Poor black areas do not have the same funding base. At the same time, local control and funding of schools is a fundamental value that most people support. Better off whites are willing to accept higher property taxes to fund their local schools. They aren't so willing to see that money flushed down the toilet in a district like Ferguson where the culture regards education as "acting white."
I suspect DB's stats ignore state and federal funding, which disproportionately flows to poorer districts.
The sad fact is there is zero correlation between funding and outcomes, as desperately as liberals like to pretend there is. There is a strong correlation between family respect for education and outcomes. I would argue there is also a negative correlation between the amount of slack given troublemakers in schools and outcomes. In typical liberal fashion though, the administration is pushing schools to tolerate more and more abusive and disruptive behavior under the guise of civil rights. Liberals will always opt for coddling a minority even if it means ruining the chance for a decent education for every other kid in the class.