9. The firm's direct-labor rate variance was $4,800 unfavorable. Actual labor was 24,000 direct-labor hours, at a cost of $168,000, for 25,000 units of finished product that require 1 hour of direct labor each, at standard. What is the standard rate per direct-labour hour ? a. $7.00 b. $6.80 c. None of the above . d. $7.20