What is the average Money ( $ ), when Country is "United States", and when To par is "+3"?
CREATE TABLE "final_leaderboard" (
  "place" text,
  "player" text,
  "country" text,
  "score" text,
  "to_par" text,
  "money" real
);
SELECT AVG("money") FROM "final_leaderboard" WHERE "country"='united states' AND "to_par"='+3';