CREATE TABLE "4_axle_units" (
  "model" text,
  "build_date" text,
  "total_produced" real,
  "wheel_arrangement" text,
  "prime_mover" text,
  "power_output" text
);

Question: What is the average total produced when the prime mover is 12-251c?
SQL: SELECT AVG("total_produced") FROM "4_axle_units" WHERE "prime_mover"='12-251c';

Question: What is the build date when total produced is 2?
SQL: SELECT "build_date" FROM "4_axle_units" WHERE "total_produced"=2;

Question: What is the smallest total produced with a model of M-420?
SQL: SELECT MIN("total_produced") FROM "4_axle_units" WHERE "model"='m-420';

Question: What is the prime mover for a build date in 1975?
SQL: SELECT "prime_mover" FROM "4_axle_units" WHERE "build_date"='1975';

Question: What model has a total produced more than 5 and a prime move of 12-251c?
SQL: SELECT "model" FROM "4_axle_units" WHERE "total_produced">5 AND "prime_mover"='12-251c';