If the problem is that children of poor parents have a financial problem getting education, create an organization that will search for talented poor children, and give them money and other support.

Vague. How do you find the talent among poor people? This is made more difficult by the fact that the cultural influences of their environment may be steering them away from attempting to demonstrate such talents of their own initiative.

If the problem is that children of uneducated parents can't get knowledge from their parents, create good educational DVDs and distribute them freely to poor people.

What if (as is probable,) educational DVDs are strictly inferior to receiving qualified hands-on assistance? A DVD can't correct you if you misunderstand an explanation, or notice when your attention is lagging, or recognize your learning style and focus its efforts on addressing it. Also, the parents of disadvantaged children are a lot less likely to sit down and help them with their homework. A DVD cannot sit down with a student and help them do their homework.

There's a point where people are liable to say "This is just too much effort for the government to go to to assist disadvantaged students, we can't hold their hands the entire way," but the effort that more advantaged families frequently put into their own childrens' education is extensive and not easy to replicate on a mass scale.

If the problem is that poor people have a culture where education is low-status, apply some propaganda (e.g. try to associate education with something they already consider high-status).

Vague again. What sort of propaganda do you think would work well enough to meaningfully address the culture gap? "Apply some propaganda" is about as helpful advice as "use rationality."

It's easy to say "Find the specific causes and address them." It's much harder to say exactly how to find out in the first place exactly what the significant causes are, let alone how to resolve them.

I don't think it's a conceptually hard problem.

As I said in my response to Viliam_Bur, it's easy to say "find out what the relevant factors are, address those," much harder to detail exactly how one works out what the significant factors are, let alone how to best address them.

Keep in mind that sorting by IQ is still a strong political taboo, and more politically viable proxies, such as SAT scores, are liable to be corrupted by factors such as SAT prep. Plus, target minorities are subject to an IQ gap which may be due to some of the cultural and/or economic factors which the policy is intended to address in the first place, in which case sorting by IQ would compound the original problem.

Note that if you do care about the race balance alone,

I don't see why this is a reasonable thing to care about.

This is true, but it seems to me that buybuydandavis would prefer a system that attempts to isolate causes of privilege independent of race, and my point is that this is likely to be a lot harder than one which isn't race-blind.