CREATE TABLE table_27714573_1 (us_viewers__millions_ VARCHAR2, directed_by VARCHAR2)

how many millions of north american viewers had the episode whose director was Michael Lembeck?
SELECT us_viewers__millions_ FROM table_27714573_1 WHERE directed_by = "Michael Lembeck"
SELECT "us_viewers__millions_" FROM "table_27714573_1" WHERE "Michael Lembeck" = "directed_by"