Determine the amount to be added to Allowance for Doubtful Accounts in each of the following cases and indicate the ending balance in each case. a. Credit balance of $490 in Allowance for Doubtful Accounts just prior to adjustment. Using the aging method, the balance of Allowance for Doubtful Accounts is estimated as $8,890. Amount added Ending balance b. Credit balance of $490 in Allowance for Doubtful Accounts just prior to adjustment. Bad debt expense is estimated at 1% of credit sales, which totaled $871,000 for the year. Amount added Ending balance