Name the average DDR3 speed for model e-350
CREATE TABLE "available_processors" (
  "series" text,
  "model" text,
  "cpu_clock_m_hz" text,
  "cpu_cores" real,
  "tdp_w" text,
  "l2_cache_ki_b" text,
  "radeon_cores" real,
  "ddr3_speed" real
);
SELECT AVG("ddr3_speed") FROM "available_processors" WHERE "model"='e-350';