Pine Company provides for doubtful accounts expense at the rate of 2% of credit sales. The following data are available for 20X4: Allowance for doubtful accounts, 1/1/X4 $18,000 Accounts written off as uncollectible during 20X4 $20,000 Collection of accounts written off in prior years (customer credit was reestablished) $5,000 Credit sales year ended 12/31/X4 $1,500,000 The allowance for doubtful accounts balance at December 31, 20X4, should be