Merchandise available for sale = Inventory, May 1 + Purchases
Merchandise available for sale at cost = $125,000 + $235,000 = $360,000
Merchandise available for sale at retail = $166,667 + $313,333 = $480,000
Ratio of cost to retail price = $360,000 ÷ $480,000 = 75%
Inventory, May 31, at retail = Merchandise available for sale at retail – Sales for May
= $480,000 – $230,000 = $250,000
Inventory, May 31, at cost = Inventory, May 31, at retail × Ratio of cost to retail price
= $250,000 × 75% = $187,500