The following summarizes the aging of accounts receivable for Johnston Supplies, Inc. as of December 31, 2020: Total Number of Days Accounts Historical % Unpaid Receivable Uncollectible S126,500 2% Not yet due 1-30 days past due 89,200 12% 31-60 days past due 53,600 18% Over 60 days past due 31,800 35% What is the net accounts receivable balance after the adjusting entry was made on January 21, 2021? Why does Johnson Supplies Inc. have to adjust for bad debt expenses