CREATE TABLE table_27462177_1 (us_viewers__millions_ VARCHAR, written_by VARCHAR)

How many millions of US viewers watched the episode written by Jack Sanderson?
SELECT us_viewers__millions_ FROM table_27462177_1 WHERE written_by = "Jack Sanderson"
SELECT "us_viewers__millions_" FROM "table_27462177_1" WHERE "Jack Sanderson" = "written_by"