"He is a quarter Norwegian and a quarter Danish and a half Greek."
Translation:El este un sfert norvegian și un sfert danez și o jumătate grec.
Well, jumătate is the "proper" term, I don't think it makes sense to further classify the other two. All three of them are in the DEX anyway.
Side-note: I think "juma de" is functionally different. I've only heard and used it to mean "half of". So I wouldn't say: "e ora șase juma" or "vreau doar juma".