Providing for doubtful accounts

At the end of the current year, the accounts receivable account has a debit balance of $$932,000$ and sales for the year total $$10,570,000.$

The allowance account before adjustment has a debit balance of $$12,600.$ Bad debt expense is estimated at $1/4$ of $1\%$ of sales.

The allowance account before adjustment has a debit balance of $$12,600.$ An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $$40,300.$

The allowance account before adjustment has a credit balance of $$8,500.$ Bad debt expense is estimated at $1/2$ of $1\%$ of sales.

The allowance account before adjustment has a credit balance of $$8,500.$ An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $$70,600.$

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