CREATE TABLE table_3631 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Director" TEXT, "Writer ( s ) " TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( million ) " TEXT)

What is the production code when the u.s. viewers (million) is 11.76?
SELECT "Production code" FROM table_3631 WHERE "U.S. viewers (million)" = '11.76'
SELECT "Production code" FROM "table_3631" WHERE "U.S. viewers (million)" = '11.76'