At the beginning of its operations in March 2024, Shamrock Supplies Ltd. began with 7,920 units of inventory that it purchased at a cost of $7.50 each. The company's purchases during March were as follows: Shamrock Supplies uses a perpetual inventory system. (a) Calculate the cost of goods sold for March using the weighted-average cost formula. (Round calculations for cost per unit to 4 decimal places, e.g. 10.5219 and final answer to 0 decimal places, e.g. 61,052.)