7-16, 7-18, 7-20

7-16 Metal Shelf Company's standard cost for raw materials is S4.00 per pound and it is expected that each metal shelf uses two pounds of material. During October Year 2, 25,000 pounds of materials are pur- chased from a new supplier for $97,000 and 13,000 shelves are produced using 27,000 pounds of materials Which statement is a possible explanation concerning the direct materials variances