Determine the amount to be added to Allowance for Doubtful Accounts in each of the following cases:

(a)	Balance of $3,000 in the allowance account just prior to adjustment. Analysis of accounts receivable indicates doubtful accounts of $25,000. __________
(b)	Balance of $500 in the allowance account just prior to adjustment. Uncollectibles are estimated at 2% of sales, which totaled $800,000 for the year. __________