How many millions of US viewers watched the episode written by Jack Sanderson?
CREATE TABLE table_29531 (
    "No. in series" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "U.S. viewers (millions)" text,
    "Original U.S. air date" text,
    "Prod. code" real
)
SELECT "U.S. viewers (millions)" FROM table_29531 WHERE "Written by" = 'Jack Sanderson'
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 US viewers watched the episode written by Jack Sanderson? ### Input: CREATE TABLE table_29531 (
    "No. in series" real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "U.S. viewers (millions)" text,
    "Original U.S. air date" text,
    "Prod. code" real
) ### Response: SELECT "U.S. viewers (millions)" FROM table_29531 WHERE "Written by" = 'Jack Sanderson'