gravenhurst, inc. provided the following aging of its receivables at december 31. age of accounts receivables balance estimated % uncollectible 0-30 days $420,000 0.5% 31 to 60 days 200,000 5.2% 61 to 90 days 75,000 10.3% 91 to 120 days 35,000 21.5% over 121 days 15,000 75.2% total $745,000 during the year, $22,500 of receivables were written off. the balance at the beginning of the year in the allowance account was a credit of $25,000. how much will gravenhurst report as bad debt expense for the year?