Dr Crown, a dentist uses the balance sheet approach to estimate the uncollectable accounts expense. At year-end, an aging of A/R showed the following groupings: a Not yet due $255,000 b 1-30 days past due $132,000 c 31-60 days past due $38,000 d 61-90 days past due $9,000 e Over 90 days past due $29,000 Based on experience, she estimates the percentages of the uncollectable amounts to be a 2% b 5% c 10% d 25% e 60% The allowance for her doubtful account at the end of the year before adjustments showed a