Record the following transactions on the books of Nao Co.
  (a) On July 1, Nao Co. sold merchandise on account to Bustamante Inc. for $15,200, terms 2/10, n/30.
  (b) On July 8, Bustamante Inc. returned merchandise worth $3,800 to Nao Co.
  (c) On July 11, Bustamante Inc. paid for the merchandise.