Slick Corporation is a small producer of synthetic motor oil. During May, the company produced 5,000 cases of lubricant. Each case contains 12 quarts of synthetic oil. To achieve this level of production, Slick purchased and used 16,500 gallons of direct materials at a cost of $20,891. It also incurred average direct labor costs of $13 per hour for the 4,240 hours worked in May by its production personnel. Manufacturing overhead for the month totaled $9,352, of which $2,200 was considered fixed. Slick's standard cost information for each case of synthetic motor oil is as follows. Direct materials standard price Standard quantity allowed per case. Direct labor standard rate Standard hours allowed per case Fixed overhead budgeted Normal level of production Variable overhead application rate: Fixed overhead application rate ($2,600 5,200 cases) Total overhead application rate $ 1.30 per gallon 3.25 gallons 16 per hour $ 0.75 direct labor hours $2,600 per month 5,200 cases per month $ 1.50 per case 0.50 per case $ 2.00 per case Required: a. Compute the materials price and quantity variances. b. Compute the labor rate and efficiency variances. c. Compute the manufacturing overhead spending and volume variances. d. Prepare the journal entries to: 1. Charge materials (at standard) to Work in Process. 2. Charge direct labor (at standard) to Work in Process. 3. Charge manufacturing overhead (at standard) to Work in Process. 4. Transfer the cost of the 5,000 cases of synthetic motor oil produced in May to Finished Goods. 5. Close any over- or underapplied overhead to cost of goods sold.