What is the average size (cents) with an interval of major third and size (steps) more than 5
CREATE TABLE "size_of_intervals_in_15_equal_temperamen" (
  "interval_name" text,
  "size_steps" real,
  "size_cents" real,
  "just_ratio" text,
  "just_cents" real,
  "error" text,
  "audio" text
);
SELECT AVG("size_cents") FROM "size_of_intervals_in_15_equal_temperamen" WHERE "interval_name"='major third' AND "size_steps">5;