New Jersey Valve Company manufactured 7,800 units during January of a control valve used by milk processors in its Camden plant. Records indicated the following: Direct labor 40,100 hr. at $14.60 per hr. Direct material purchased 25,000 lb. at $2.60 per lb. Direct material used 23,100 lb. The control valve has the following standard prime costs: Direct material 3 lb. at $2.50 per lb. $ 7.50 Direct labor 5 hr. at $15.00 per hr. 75.00 Standard prime cost per unit $ 82.50 Required: Prepare a schedule of standard production costs for January, based on actual production of 7,800 units. For the month of January, compute the following variances.