CREATE TABLE "table1_22078972_2" (
  "no_in_series" real,
  "no_in_season" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "u_s_viewers_millions" text
);

Question: What's the series number of the episode whose writer is David North?
SQL: SELECT MAX("no_in_series") FROM "table1_22078972_2" WHERE "written_by"='David North';

Question: What's the series number of the episode seen by 17.04 million people in the US?
SQL: SELECT MAX("no_in_series") FROM "table1_22078972_2" WHERE "u_s_viewers_millions"='17.04';

Question: What's the title of the episode first seen by 18.15 million people in the US?
SQL: SELECT "title" FROM "table1_22078972_2" WHERE "u_s_viewers_millions"='18.15';

Question: How many millions of people in the US saw the episode with series number 103?
SQL: SELECT "u_s_viewers_millions" FROM "table1_22078972_2" WHERE "no_in_series"=103;