Depreciation on the company's equipment for the year is computed to be $18,000. the prepaid insurance account had a $6,000 debit balance at december 31 before adjusting for the costs of any expired coverage. an analysis of the company's insurance policies showed that $1,100 of unexpired insurance coverage remains. the office supplies account had a $700 debit balance at the beginning of december; and $3,480 of office supplies were purchased in december. the december 31 physical count showed $300 of supplies available. two-thirds of the work related to $15,000 of cash received in advance was performed this period. the prepaid rent account had a $6,800 debit balance at december 31 before adjusting for the costs of any expired coverage. an analysis of rental policies showed that $5,800 of rental coverage had expired. wage expenses of $3,200 have been incurred but are not paid as of december 31.