CREATE TABLE "table1_25996938_1" (
  "no_in_series" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_million" text
);

Question: Which episode did 18.74 million people tune in?
SQL: SELECT "title" FROM "table1_25996938_1" WHERE "u_s_viewers_million"='18.74';

Question: Which prod code was series 11?
SQL: SELECT "production_code" FROM "table1_25996938_1" WHERE "no_in_series"=11;