when the writer is Brad Kern, how many u.s viewers (in millions) had the episode?
CREATE TABLE table_21313327_1 (us_viewers__millions_ VARCHAR, written_by VARCHAR)
SELECT us_viewers__millions_ FROM table_21313327_1 WHERE written_by = "Brad Kern"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_21313327_1 (us_viewers__millions_ VARCHAR, written_by VARCHAR) Question: when the writer is Brad Kern, how many u.s viewers (in millions) had the episode? [/INST] SELECT us_viewers__millions_ FROM table_21313327_1 WHERE written_by = "Brad Kern" </s>