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 $300 in Allowance for Doubtful Accounts just prior to adjustment. Analysis of accounts receivable indicates uncollectible receivables of $8,500.

Amount added	$
Ending balance	$

b. Credit balance of $500 in Allowance for Doubtful Accounts just prior to adjustment. Uncollectible receivables are estimated at 2% of credit sales, which totaled $1,000,000 for the year.

Amount