Preble Company manufactures one product. Its variable manufacturing overhead is applied to production based on direct labor-hours and its standard cost card per unit is as follows: The company also established the following cost formulas for its selling expenses: The planning budget for March was based on producing and selling 24,000 units. However, during March the company actually produced and sold 30,600 units and incurred the following costs: a. Purchased 170,000 pounds of raw materials at a cost of $9.00 per pound. All of this material was used in production. b. Direct-laborers worked 68,000 hours at a rate of $18.00 per hour. c. Total variable manufacturing overhead for the month was $512,040. d. Total advertising, sales salaries and commissions, and shipping expenses were $340,000,$520,000, and $245,000, respectively. What is the direct labor efficiency variance for March? (Indicate the effect of each variance by selecting " F " for favorable, " U " for infavorable, and "None" for no effect (i.e., zero variance.). Input the amount as a positive value.)