please answer this

Concord Corporation operates in an industry that has a high rate of bad debts. Before any year-end adjustments, the balance in Concord's Accounts Receivable account was $590,400 and Allowance for Doubtful Accounts had a credit balance of $40,320. The year-end balance reported in the balance sheet for Allowance for Doubtful Accounts will be based on the aging schedule shown below. (a) What is the appropriate balance for Allowance for Doubtful Accounts at year-end