CREATE TABLE table_28561455_1 (no_in_series VARCHAR2, us_viewers__million_ VARCHAR2)

For how many series were there 11.84 million watchers?
SELECT no_in_series FROM table_28561455_1 WHERE us_viewers__million_ = "11.84"
SELECT "no_in_series" FROM "table_28561455_1" WHERE "11.84" = "us_viewers__million_"