CREATE TABLE table_23242968_1 (directed_by VARCHAR2, us_viewers__millions_ VARCHAR2)

Who directed the episode that had 6.76 million U.S. viewers?
SELECT directed_by FROM table_23242968_1 WHERE us_viewers__millions_ = "6.76"
SELECT "directed_by" FROM "table_23242968_1" WHERE "6.76" = "us_viewers__millions_"