10.2 What is the difference between using check digit verification and a validity check to
test the accuracy of an account number entered on a transaction record?
Check digit verification is designed to detect typographical errors such as transposing two
10.3 For each of the three basic options for replacing IT infrastructure (cold sites, hot
sites, and real-time mirroring) give an example of an organization that could use
that approach as part of its DRP. Be prepared to defend your answer.
Many solutions are possible. The important point is to justify that the method yields an
appropriate RTO for the organization. Cold sites yield RTOs measured in days; hot sites
result in RTOs measured in hours; and real-time mirroring have RTOs measured in
Cold site: smaller businesses, such as a local CPA firm. In most situations, CPA firms can
Hot site: Many businesses could function for several hours using paper-based forms until
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Accounting Information Systems
10.4 Use the numbers 10–19 to show why transposition errors are always divisible by 9.
A B B – A Divisible by 9?
Original Number Transposed Number Difference
When two numbers are transposed, the difference between the original number and the
transposed number is divisible by 9 except when the two digits have the same value.
10.5 What are some business processes for which an organization might use batch
processing?
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Batch processing may be used when master files do not need to be updated in real-time. For example, many organizations process
accounts payable in batches once a day or once a week because they do not need up-to-the-minute accuracy about the balances
10.6 Why do you think that surveys continue to find that a sizable percentage of organizations either do not have formal
disaster recovery and business continuity plans or have not tested and revised those plans for more than a year?
Likely reasons include:
Belief that “it won’t happen to us”
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Accounting Information Systems
SUGGESTED SOLUTIONS TO THE PROBLEMS
10.1 Match the following terms with their definitions:
__r__ 1. business continuity plan (BCP) a. A file used to store information for long periods
of time.
__m__ 11. recovery point objective (RPO) j. An application control that makes sure an
account does not have a balance after
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Accounting Information Systems
processing.
__l__ 12. recovery time objective (RTO) k. An application control that compares the sum
of a set of columns to the sum of a set of rows.
u. A data-entry application control that could be
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Accounting Information Systems
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Accounting Information Systems
10.2 Excel Problem
Enter the following data into a spreadsheet and then perform the following tasks:
Employe
e
Number
Pay rate
Hours
worked Gross Pay Deductions Net pay
12355 10.55 38 400.90 125.00 275.90
a. Calculate examples of these batch totals:
A hash total
A financial total
A record count
b. Assume the following rules govern normal data:
Employee numbers are five-digits in length and range from 10000 through 99999.
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Accounting Information Systems
Maximum pay rate is $25, and minimum is $9.
Hours worked should never exceed 40.
Deductions should never exceed 40% of gross pay.
Give a specific example of an error or probable error in the data set that each of the following controls would detect:
Field check
Limit check
Reasonableness test
Cross-footing balance test
c. Create a control procedure that would prevent, or at least detect, each of the errors in the data set.
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Accounting Information Systems
Alternatively, you could write the following IF statement to perform the same test:
Pay rate too high or too low
This range test could be programmed using the data validation tool as follows:
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Accounting Information Systems
Alternatively, this logical test would catch such errors and display an appropriate error message:
Hours worked too high
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