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 $440 in Allowance for Doubtful Accounts just prior to adjustment. Analysis of Accounts Receivable indicates uncollectible receivables of $8,580. Amount added $fill in the blank 1 Ending balance $fill in the blank 2 (b) Credit balance of $440 in Allowance for Doubtful Accounts just prior to adjustment. Uncollectible receivables are estimated at 3% of credit sales, which totaled $1,170,000 for the year. Amount added $fill in the blank 3 Ending balance $fill in the blank 4