CREATE TABLE "table1_2102945_1" (
  "episode" text,
  "broadcast_date" text,
  "run_time" text,
  "viewers_in_millions" text,
  "archive" text
);

Question: When there are  7.4 million viewers how many episodes are there?
SQL: SELECT COUNT("episode") FROM "table1_2102945_1" WHERE "viewers_in_millions"='7.4';

Question: When 24:31 is the run time how many measurements of viewers (in millions) are there?
SQL: SELECT COUNT("viewers_in_millions") FROM "table1_2102945_1" WHERE "run_time"='24:31';

Question: When 24:31 is the run time how many millions of viewers are there?
SQL: SELECT "viewers_in_millions" FROM "table1_2102945_1" WHERE "run_time"='24:31';

Question: When there are 7.5 million viewers what is the archive?
SQL: SELECT "archive" FROM "table1_2102945_1" WHERE "viewers_in_millions"='7.5';