The following materials standards have been established for a particular raw material used in the company's sole product: Standard quantity per unit of output............ Standard price........ 0.5 pound $16.60 per pound The following data pertain to operations concerning the product for the last month: Actual cost of materials......... Actual materials used in production.......... Actual output......... $34,650 1,900 pounds 4,200 units What is the materials quantity variance for the month? $3,320 U $3,110 F $3,110 U O $3,320 F $6,430 F