Credit Losses Based on Accounts Receivable Aging Graham Inc. analyzed its accounts receivable balances at December 31 , and arrived at the aged balances listed below, along with the percentage that is estimated to be uncollectible: The company handles credit losses using the allowance method. The credit balance of the Allowance for Doubtful Accounts is $2,496 on December 31 , before any adjustments. a. Determine the amount of the adjustment for estimated credit losses on December 31. b. Determine the financial statement effect of a write off of the Matthews Company's account on April 10 of the following year in the amount of $680. Use negative signs with answers, when appropriate. If a transaction increases and decreases the same Balance Sheet category, enter the increase amount in the first row and the decrease amount directly below (in the second row)