What's the previous conference of Fountain City with a size more than 287?
CREATE TABLE "membership" (
  "school" text,
  "location" text,
  "mascot" text,
  "size" real,
  "ihsaa_class" text,
  "num_county" text,
  "year_joined" real,
  "previous_conference" text
);
SELECT "previous_conference" FROM "membership" WHERE "size">287 AND "location"='fountain city';