Apr. 2 Purchased $4,200 of merchandise from Lyon Company with credit terms of 2/15, n/60, invoice dated April 2, and FOB shipping point. 3 Paid $235 cash for shipping charges on the April 2 purchase. 4 Returned to Lyon Company unacceptable merchandise that had an invoice price of $500. 17 Sent a check to Lyon Company for the April 2 purchase, net of the discount and the returned merchandise. 18 Purchased $9,100 of merchandise from Frist Corp. with credit terms of 1/10, n/30, invoice dated April 18, and FOB destination. 21 After negotiations, received from Frist a $500 allowance toward the $9,100 owed on the April 18 purchase. 28 Sent check to Frist paying for the April 18 purchase, net of the allowance and the discount. Prepare journal entries to record each of the above merchandising transactions assuming that the buyer uses the periodic inventory system and the gross method.