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 $480 in Allowance for Doubtful Accounts just prior to adjustment. Analysis of Accounts Receivable indicates uncollectible receivables of $7, 100. Amount added: $ Ending balance: $ (b) Credit balance of $480 in Allowance for Doubtful Accounts just prior to adjustment. Uncollectible receivables are estimated j at 2% of credit sales, which totaled $808,000 for the year. Amount added: $ Ending balance: $