What is the average bronze with a rank of 4 and less than 1 silver?
CREATE TABLE "medal_table" (
  "rank" real,
  "nation" text,
  "gold" real,
  "silver" real,
  "bronze" real,
  "total" real
);
SELECT AVG("bronze") FROM "medal_table" WHERE "rank"=4 AND "silver"<1;