What was the attendance for the game when the challenge leader was at Big East (4-2)?
CREATE TABLE "table1_20540006_6" (
  "date" text,
  "time" text,
  "big_east_team" text,
  "sec_team" text,
  "location" text,
  "television" text,
  "attendance" real,
  "winner" text,
  "challenge_leader" text
);
SELECT MAX("attendance") FROM "table1_20540006_6" WHERE "challenge_leader"='Big East (4-2)';