CREATE TABLE table_30760 ("No in. series" FLOAT, "No in. season" FLOAT, "Title" CLOB, "Original air date" CLOB, "Production Code" FLOAT, "U.S. viewers  ( millions ) " CLOB)

How many millions of US viewers watched the episode titled 'Happy Howl-o-ween'?
SELECT "U.S. viewers (millions)" FROM table_30760 WHERE "Title" = 'Happy Howl-O-Ween'
SELECT "U.S. viewers (millions)" FROM "table_30760" WHERE "Title" = 'Happy Howl-O-Ween'