CREATE TABLE "table1_15026994_3" (
  "num" real,
  "episode" text,
  "writer" text,
  "director" text,
  "original_air_date" text,
  "viewing_figure" text
);

Question: Who is the director of the episode at entry number 13? 
SQL: SELECT "director" FROM "table1_15026994_3" WHERE "num"=13;

Question: Who wrote the episode that David Tucker directed?
SQL: SELECT COUNT("writer") FROM "table1_15026994_3" WHERE "director"='David Tucker';

Question: Which episode has been viewed 6.34 million times? 
SQL: SELECT "episode" FROM "table1_15026994_3" WHERE "viewing_figure"='6.34 million';

Question: What is the original air date of the episode directed by Paul Marcus?
SQL: SELECT "original_air_date" FROM "table1_15026994_3" WHERE "director"='Paul Marcus';

Question: Which numerical entry corresponds to "Episode 9"?
SQL: SELECT COUNT("num") FROM "table1_15026994_3" WHERE "episode"='\"Episode 9\"';