What episode number in the series had 2.528 million u.s. viewers?
CREATE TABLE table_3020 (
    "Overall" real,
    "No. in series" real,
    "Title" text,
    "Directed by" text,
    "Original air date" text,
    "U.S. viewers (in millions)" text
)
SELECT "No. in series" FROM table_3020 WHERE "U.S. viewers (in millions)" = '2.528'
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 episode number in the series had 2.528 million u.s. viewers? ### Input: CREATE TABLE table_3020 (
    "Overall" real,
    "No. in series" real,
    "Title" text,
    "Directed by" text,
    "Original air date" text,
    "U.S. viewers (in millions)" text
) ### Response: SELECT "No. in series" FROM table_3020 WHERE "U.S. viewers (in millions)" = '2.528'