Waddell Industries has a past history of uncollectible accounts, as follows. Estimate the allowance for doubtful accounts, based on the aging of receivables schedule you completed in Exercise 9-8.

Data From Exercise 9-8:

The accounts receivable clerk for Waddell Industries prepared the following partially completed aging of receivables schedule as of the end of business on August 31:

The following accounts were unintentionally omitted from the aging schedule and not included in the preceding subtotals:

a. Determine the number of days past due for each of the preceding accounts as of August 31.
b. Complete the aging of receivables schedule by adding the omitted accounts to the bottom of the schedule and updating the totals.