4. On December 31, 2017, when its Allowance for Doubtful Accounts had a credit balance of $2,000, Arrow Co. estimates that 10% of its accounts receivable balance of $100,000 will become uncollectible and records the necessary adjustment to Allowance for Doubtful Accounts. On September 10, 2018, Arrow Co. determined that S. Adam's account was uncollectible and wrote off $1,000. Balance of Accounts Receivables and Sales on December 31,2018 are $150.000 and $ 200.000 respectively. Instructions: a) Assumption1: Prepare the journal entries on December 31, 2017, September 10, 2018 and December 31, 2018. Assumption 2: On October 15, 2018, S.Adam paid the amount previously written off. Prepare the journal entries on December 31, 2017, September 10, 2018, October 15, 2018 and December 31, 2018. b) Assume that Arrow Co. estimates that 10% of its sales balance of $100,000 will become doubtful. Prepare the journal entries on December 31, 2017, September 10, 2018, and December 31, 2018.