Based on the provided customer account balances and estimated uncollectible percentages, the document estimates the uncollectible accounts amount for each age interval to calculate the total allowance for doubtful accounts as of December 31, 2014. It lists the account balances in different aging categories, from current to over 180 days past due, and the estimated uncollectible percentage for each category, ranging from 0.5% to 80%, to determine the proper balance sheet amount for allowance for doubtful accounts.