Need help with "allowence for doubtful accounts"

Bad Debt Expense: Percentage of Credit Sales Method Bradford Plumbing had the following data for a recent year: Credit sales $547,900 8,740 Allowance for doubtful accounts, 1/1 (a credit balance) Accounts receivable, 1/1 42,340 Collections on account receivable 489,770 14,250 Accounts receivable written off Bradford estimates that 2.7% of credit sales will eventually default. Required: 1. Compute bad debt expense for the year (rounding to the nearest whole number). 18,081 2. Determine the ending balances in accounts receivable and allowance for doubtful accounts. Ending Balance Accounts receivable 86,220 Allowance for doubtful accounts