CREATE TABLE table_56998 ("Episode" TEXT, "Air date" TEXT, "Rating" FLOAT, "Share" FLOAT, "18-49  ( Rating/Share ) " TEXT, "Viewers  ( m ) " FLOAT, "Rank  ( timeslot ) " TEXT)

what is the average rating when the air date is november 23, 2007?
SELECT AVG("Rating") FROM table_56998 WHERE "Air date" = 'november 23, 2007'
SELECT AVG("Rating") FROM "table_56998" WHERE "Air date" = 'november 23, 2007'