Who was the opponent on the date of November 29, 1970 and the attendance was less than 31,427?
CREATE TABLE "schedule" (
  "week" real,
  "date" text,
  "opponent" text,
  "result" text,
  "attendance" real
);
SELECT AVG("week") FROM "schedule" WHERE "date"='november 29, 1970' AND "attendance"<'31,427';