The standards for product G78V specify 4.5 direct labor-hours per unit at $12.50 per direct labor-hour. Last month 1,640 units of product G78V were produced using 7,410 direct labor-hours at a total direct labor wage cost of $90,220. Required: a. What was the labor rate variance for the month? b. What was the labor efficiency variance for the month? (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)