Assignment
An auditor is applying statistical sampling for attributes to the testing of extensions of 1000 line items on sales invoices. A deviation is defined as an extension mistake on a line (i.e. line #39 quantity of 10 and unit price of $100 is calculated as $900).
The auditor decides to use a 10% Risk of Overreliance, a Tolerable Deviation Rate of 6%, and an expected population deviation rate of 2%.
Assume the following deviation condition exists in the population (the auditor would not know this):
Line # Amount of deviation overstated (understated)
39 $ (100)
81 150
202 900
220 700
240 950
291 (300)
526 (1126)
600 1000
798 500
840 350
890 925
906 (820)
908 (1200)
971 200
Required
a. Calculate the sample size.
b.Take ONE sample using random selection. Regardless of your answer to part "a", use a sample size of 100 lines. If you select a line number listed in the preceding deviation table, assume that a deviation is found.
c. Quantitatively evaluate your sample results. [Use the "sample decision rule".]
d. Assume that your sample contains so many deviations that you as the auditor conclude that controls are not acceptable. Develop a "population decision rule", as suggested in class. Use the population decision rule to conclude that controls would be acceptable in this case.