Clark Company estimated the net realizable value of its accounts receivable as of December 31, 2019, to be $177,000, based on an aging schedule of accounts receivable. Clark has also provided the following information: The accounts receivable balance on December 31, 2019 was $189,400. Uncollectible accounts receivable written off during 2019 totaled $13,200. The allowance for doubtful accounts balance on January 1, 2019 was $17,400. How much is Clark's 2019 bad debt expense