CREATE TABLE "membership" (
  "school" text,
  "location" text,
  "mascot" text,
  "county" real,
  "enrollment" text,
  "ihsaa_class" text,
  "year_joined" real,
  "previous_conference" text
);

Question: Which school has an enrollment of A and had lost river as their previous conference?
SQL: SELECT "school" FROM "membership" WHERE "previous_conference"='lost river' AND "enrollment"='a';

Question: What is the average year joined of the 277 county?
SQL: SELECT AVG("year_joined") FROM "membership" WHERE "county"=277;

Question: What is the IHSAA class of the county that is less than 228?
SQL: SELECT "ihsaa_class" FROM "membership" WHERE "county"<228;