Providing for Doubtful Accounts

At the end of the current year, the accounts receivable account has a debit balance of $881,000 and sales for the year total $9,980,000.

1. The allowance account before adjustment has a credit balance of $11,900. Bad debt expense is estimated at 3/4 of 1% of sales.
2. The allowance account before adjustment has a credit balance of $11,900. An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $38,100.
3. The allowance account before adjustment has a debit balance of $7,200. Bad debt expense is estimated at 1/2 of 1% of sales.
4. The allowance account before adjustment has a debit balance of $7,200. An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $59,800.

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