On December 31, 2017, when its accounts receivable were $276,000 and its account Allowance for Doubtful Accounts had an unadjusted debit balance of $1,800, Marx Corp. estimated that $15,500 of its accounts receivable would become uncollectible, and it recorded the bad debts adjusting entry. On May 11, 2018, Marx determined that Fei Ya Cheng's account was uncollectible and wrote off $1,700. On November 12, 2018, Cheng paid the amount previously written off.