What is the Attendance with a Week that is 18?
CREATE TABLE table_7647 (
    "Week" real,
    "Date" text,
    "Opponent" text,
    "Game Site" text,
    "Final Score" text,
    "Record" text,
    "Attendance" text
)
SELECT "Attendance" FROM table_7647 WHERE "Week" = '18'
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: What is the Attendance with a Week that is 18? ### Input: CREATE TABLE table_7647 (
    "Week" real,
    "Date" text,
    "Opponent" text,
    "Game Site" text,
    "Final Score" text,
    "Record" text,
    "Attendance" text
) ### Response: SELECT "Attendance" FROM table_7647 WHERE "Week" = '18'