How many millions of people watched the episode 'The Grandfather'?
CREATE TABLE table_3638 (
    "No. in series" real,
    "No. in season" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "U.S. viewers (in millions)" text
)
SELECT "U.S. viewers (in millions)" FROM table_3638 WHERE "Title" = 'The Grandfather'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: How many millions of people watched the episode 'The Grandfather'? ### Input: CREATE TABLE table_3638 (
    "No. in series" real,
    "No. in season" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "U.S. viewers (in millions)" text
) ### Response: SELECT "U.S. viewers (in millions)" FROM table_3638 WHERE "Title" = 'The Grandfather'