Question 13 1.5 pts When aging of accounts receivable is used, each age group is multiplied by its own estimated uncollectible percentage to determine each age group's estimated uncollectible amount. The sum of the amounts thus determined is the O required ending balance for the allowance for doubtful accounts. O amount that should be written off as uncollectible for the year. increase to the existing credit balance in the allowance for doubtful accounts. amount of bad debt expense for the year