CREATE TABLE table_38942 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" FLOAT)

What is the average week that there was a game with less than 18,517 fans attending and occurred on November 21, 1954?
SELECT AVG("Week") FROM table_38942 WHERE "Attendance" < '18,517' AND "Date" = 'november 21, 1954'
SELECT AVG("Week") FROM "table_38942" WHERE "Attendance" < '18,517' AND "Date" = 'november 21, 1954'