Kubota Co. is a wholesaler of office supplies. An aging of the company's accounts receivable on December 31, 2006, and a historical analysis of the percentage of uncollectible accounts in each age category are as follows:
Age Interval Balance Percent Uncollectible
Not past due $450,000 2%
1-30 days past due 110,000 4
31-60 days past due 51,000 6
61-90 days past due 12,500 20
91-180 days past due 7,500 60
Over 180 days past due 5,500 80
$636,500
Estimate what the proper balance of the allowance for doubtful accounts should be as of December 31, 2006.