Highest smaller than 3,378, and a Stadium of cappielow has what average capacity?
CREATE TABLE "attendances" (
  "team" text,
  "stadium" text,
  "capacity" real,
  "highest" real,
  "lowest" real,
  "average" real
);
SELECT AVG("capacity") FROM "attendances" WHERE "highest"<'3,378' AND "stadium"='cappielow';