CREATE TABLE table_24938621_3 (production_code VARCHAR, us_viewers__million_ VARCHAR)

What is the production code of the episode that had 5.43 million viewers?
SELECT production_code FROM table_24938621_3 WHERE us_viewers__million_ = "5.43"
SELECT "production_code" FROM "table_24938621_3" WHERE "5.43" = "us_viewers__million_"