CREATE TABLE table_28760804_1 (directed_by VARCHAR, us_viewers__million_ VARCHAR)

How many directors got 6.79 million U.S. viewers from their episodes?
SELECT COUNT(directed_by) FROM table_28760804_1 WHERE us_viewers__million_ = "6.79"
SELECT COUNT("directed_by") FROM "table_28760804_1" WHERE "6.79" = "us_viewers__million_"