Answer:
Bad debts expense Debit $ 600
Allowance for Uncollectible expenses Credit $ 600
Explanation:
The allowance for uncollectible accounts is estimated usually on the basis of a percentage of credit sales. The data in the question indicates that the estimated losses from uncollectible accounts is $ 1,000.
The unadjusted balance is $ 400, so the adjusting entry is for the balancing amount, i.e. $ 600. It is debited to bad debts and credited to allowance for uncollectible accounts.