Excellent Manufacturing uses a process cost system to manufacture sensors for the security industry. The following information pertains to operations for the month of March:

Units

Beginning work-in-process inventory, March 1

12,600

Started production during March

115,500

Completed production during March

92,400

Ending work-in-process inventory, March 31

35,700

The beginning inventory was 65% complete with respect to materials and 25% complete with respect to conversion costs. The ending inventory was 80% complete with respect to materials and 45% complete with respect to conversion costs. Costs pertaining to the month of March are as follows: Beginning inventory costs: materials = $46,200; conversion cost = $32,025

Costs incurred during March: materials used = $617,400; conversion cost = $655,200 Which of the following is the unit cost of materials calculated using the weighted average method? (Note: Round your answer to two decimal places.)

a. $5.46

b. $5.49

c. $5.00

d. $4.50