Following are errors, frauds, or other circumstances that an auditor might encounter as a result of applying year end substantive tests to accounts receivable as of December 31, 1999:

a. Sales totaling $12,500 were shipped on January 2, 2000 and recorded on December 31, 1999.

b. Balances in selected individual customer accounts do not reconcile with supporting documentation (e.g., sales invoices, cash receipts).

c. Not all sales transactions are recorded.

d. The aged trial balance prepared by the client includes a customer account within the 30- to 60-day category that is actually 120 days old.

e. Positive confirmations were not returned by 27 of 100 mailed receivables confirmations.

f. Actual write offs during 1999 of receivables arising from 1998 sales were greater than the December 31, 1999 allowance for doubtful accounts.

Required: 

For each of the preceding items indicate: 

(1) procedures that might address the error, fraud, or circumstance 

(2) the financial statement assertion addressed by each procedure.