On May 7, Lockmiller Company purchased on account 12,000 units of raw materials at $6 per unit. During May, raw materials were requisitioned for production as follows: 8,400 units for Job 275 at $6 per unit and 2,150 units for Job 310 at $4 per unit. Journalize the entry on May 7 to record the purchase and on May 31 to record the requisition from the materials storeroom.