Which Number of households has a County of cook, and Population smaller than 5,176?
CREATE TABLE "minnesota_counties_ranked_by_per_capita_" (
  "county" text,
  "per_capita_income" text,
  "median_household_income" text,
  "median_family_income" text,
  "population" real,
  "number_of_households" real
);
SELECT AVG("number_of_households") FROM "minnesota_counties_ranked_by_per_capita_" WHERE "county"='cook' AND "population"<'5,176';