An aging analysis of Sweetwater Limited's accounts receivable at December 31, 2021 and 2020, sho Additional information: 1. At December 31,2020, the unadjusted balance in Allowance for Doubtful Accounts was a cr Additional information: 1. At December 31,2020, the unadjusted balance in Allowance for Doubtful Accounts was a credit of $9,600. 2. In 2021,$42,400 of accounts were written off as uncollectible and $3,000 of accounts previously written off wer recovered. (a1) Prepare an aging schedule to calculate the estimated uncollectible accounts at December 31, 2020 and 2021 . Note tha estimated percentages uncollectible are the same for both years. Total estimated allowance balance at Dec. 31, 2020