The standards for product TB12 specify 4.4 direct labor-hours per unit at $12.00 per direct labor-hour Last month 1.630 units of product TB12 were produced using 7,220 direct labor-hours at a total direct labor wage cost of $80,220. 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.)