CREATE TABLE table_3638 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "U.S. viewers  ( in millions ) " CLOB)

How many millions of people watched the episode 'The Grandfather'?
SELECT "U.S. viewers (in millions)" FROM table_3638 WHERE "Title" = 'The Grandfather'
SELECT "U.S. viewers (in millions)" FROM "table_3638" WHERE "Title" = 'The Grandfather'