Koss Co. Ltd. began operations on January 1, 2015. It had the following transactions during 2015, 2016, and 2017. 2015 Dec. 31 Estimated uncollectible accounts as $5,000 (calculated 2016 Apr. 15 Wrote off the balance of N. Lang, $700 as 2% of sales) 8Wrote off $3,000 of miscellaneous customer accounts Aug. Dec. Mar. 6 as uncollectible Estimated uncollectible accounts as $4,000 (1%% of sales) Recovered $200 from N. Lang, whose account was written off in 2016; no further recoveries are expected Wrote off as uncollectible $4,000 of miscellaneous customer accounts Estimated uncollectible accounts as $4,500 (1%% of sales) 31 2017 Sept. 4 Dec. 31