Journalize the adjusting entry needed on December 31, the company's year-end, for each of the following independent cases affecting East Coast Communications. (Click the icon to view the independent cases.) a. The beginning balance of Supplies was $6,400. During the year, the company purchased supplies costing $8,000, and at December 31, the inventory of supplies remaining on hand is $4,400 Record the supplies expense for the year, Journal Entry Date December 31 Accounts Debit Credit Compute the overhead rates using the activity-based costing approach. Machining per machine hour Machine setup $ per setup hour