Then you would say "The eleven Brazilian boys are fourth" not the fourth. I don't think you can say "the fourth" in the context you gave - adding "the" only makes sense if it's followed by something, e.g. "the eleven Brazilian boys are the fourth team to win the title."
Without a WHOLE lot more context, this is just as nonsensical in Hungarian as in English. In English, it would be vastly more understandable as "The eleven Brazilian boys are in fourth place".