Which Week has an Attendance smaller than 70,056, and an Opponent of at minnesota vikings?
CREATE TABLE "schedule" (
  "week" real,
  "date" text,
  "opponent" text,
  "result" text,
  "record" text,
  "attendance" real
);
SELECT COUNT("week") FROM "schedule" WHERE "attendance"<'70,056' AND "opponent"='at minnesota vikings';