Rankine Company estimates its bad debt expense by aging its accounts receivable and applying percentages to various age groups of the accounts. Rankine calculated a total of $4,000 in possible credit losses as of December 31. Accounts Receivable has a balance of $128,000, and the Allowance for Doubtful Accounts has a balance of $500 before adjustment at December 31. What is the amount of the December 31 adjustment to provide for credit losses? What is the net amount of accounts receivable that should be included in current assets?