CREATE TABLE table_2108684_1 (run_time VARCHAR2, viewers__in_millions_ VARCHAR2)

What is the run time for the episode with 7.9 million viewers?
SELECT run_time FROM table_2108684_1 WHERE viewers__in_millions_ = "7.9"
SELECT "run_time" FROM "table_2108684_1" WHERE "7.9" = "viewers__in_millions_"