Japan Company produces lamps that require 3 standard hours per unit at a standard hourly rate of $15.80 per hour. Production of 3,400 units required 10,000 hours at an hourly rate of $15.30 per hour. What is the direct labor (a) rate variance, (b) time variance, and (c) total cost variance? Enter favorable variances as negative numbers. a. Direct labor rate variance b. Direct labor time variance c. Total direct labor cost variance