CREATE TABLE table_74174 ("Series #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" FLOAT, "U.S. viewers  ( million ) " TEXT)

What is the highest series # directed by ken whittingham?
SELECT MAX("Series #") FROM table_74174 WHERE "Directed by" = 'Ken Whittingham'
SELECT MAX("Series #") FROM "table_74174" WHERE "Directed by" = 'Ken Whittingham'