code: def ave_list_v3(vec_list):
      
  
      vec = Vec3(0, 0, 0)
      for v in vec_list:
          vec += v
      num_vecs = float(len(vec_list))
      vec = Vec3(vec.x / num_vecs, vec.y / num_vecs, vec.z / num_vecs)
      return vec
docs: Return the average vector of a list of vectors.