CREATE TABLE "arizona_counties_ranked_by_per_capita_in" (
  "county" text,
  "per_capita_income" text,
  "median_household_income" text,
  "median_family_income" text,
  "population" real,
  "number_of_households" real
);

Question: Median household income of $40,340, and a Number of households smaller than 64,767 is what average population?
SQL: SELECT AVG("population") FROM "arizona_counties_ranked_by_per_capita_in" WHERE "median_household_income"='$40,340' AND "number_of_households"<'64,767';