Which money has a Country of united states, and a Place of t6?
CREATE TABLE "final_round" (
  "place" text,
  "player" text,
  "country" text,
  "score" text,
  "to_par" text,
  "money" real
);
SELECT AVG("money") FROM "final_round" WHERE "country"='united states' AND "place"='t6';