Accounting for Doubtful Accounts

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 $5,200 in possible credit losses as of December 31. Accounts Receivable has a balance of $166,400 and the Allowance for Doubtful Accounts has a credit balance of $650 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? $ ?