CREATE TABLE "table1_27713721_1" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" real,
  "u_s_viewers_millions" text
);

Question: How many episodes had an audience of exactly 25.3 million viewers in the U.S.A.?
SQL: SELECT COUNT("production_code") FROM "table1_27713721_1" WHERE "u_s_viewers_millions"='25.3';