At the end of the current year, the accounts receivable account has a debit balance of $1,835,000 and sales for the year total $25,690,000. The allowance account before adjustment has a debit balance of $12,500. Bad debt expense is estimated at 1/2 of 1% of sales. The allowance account before adjustment has a debit balance of $12,500. An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $162,000. The allowance account before adjustment has a credit balance of $26,810. Bad debt expense is estimated at 3/4 of 1% of sales. The allowance account before adjustment has a credit balance of $26,810. An aging of the accounts in the customer ledger indicates estimated doubtful accounts of $171,200. Determine the amount of the adjusting entry to provide for doubtful accounts under each of the assumptions (a through d) listed above.