At the end of the current year, the accounts receivable account has a debit balance of $1,103,000 and sales for the year total $12,500,000.

1. The allowance account before adjustment has a debit balance of $14,900. Bad debt expenseis estimated at 1/2 of 1% of sales.
2. The allowance account before adjustment has a debit balance of $14,900. An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $47,700.
3. The allowance account before adjustment has a credit balance of $8,900. Bad debt expense is estimated at 1/4 of 1% of sales.
4. The allowance account before adjustment has a credit balance of $8,900. An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $73,900.

Determine the amount of the adjusting entry to provide for doubtful accounts under each of the assumptions (a through d) listed above.