Answer:
The Journal entries are as follows:
(i) Allowance for doubtful accounts    Dr.  $21,000
To Accounts receivables                       $21,000
(To written of accounts receivables)
(ii) Accounts receivables A/c       Dr. $1,200
To Allowance for doubtful accounts          $1,200
(To reinstate account previously written off)
(iii) Cash A/c            Dr. $1,200
To Accounts receivables           $1,200
(To record collection of accounts previously written off)
(iv) Bad debts Expense ($625,000×10% + $12,200) Dr. $50,300
To Allowance for doubtful accounts                         $50,300           Â
(To record bad debts expense)