What was the number of dances for the competition finish of 3?
CREATE TABLE "average_chart" (
  "rank_by_average" real,
  "competition_finish" real,
  "couple" text,
  "total" real,
  "number_of_dances" real,
  "average" text
);
SELECT MAX("number_of_dances") FROM "average_chart" WHERE "competition_finish"=3;