Answer:
Compute the Allowance for Doubtful Accounts as of year end by adding the Uncollectible Accounts Expense (which is 1% of sales on account) and Uncollectible Accounts Charged off during the Year since those accounts are deemed uncollectible and are deducted from Accounts Receivable and removed from the allowance account.
Allowance for Doubtful Accounts = [Sales on Account × 1%] - Write-offs
Allowance for Doubtful Accounts = [$320, 000 × 0.01] - $1,400
Allowance for Doubtful Accounts = $1,800
The Allowance for Doubtful Accounts balance as of year end is $1,800.