Check that only a single character is used. (field check)
Alternatively, the following IF statement also checks this:
Field 4 – Time of take off:
Field check to verify that the field contains valid time format.
Field 5 – Time of landing:
a. Suggest other controls to minimize the risk of input errors.
prompting to request each required input item.
10.4 The first column in Table 10-3 lists transaction amounts that have been summed to obtain a batch total. Assume that all
data in the first column are correct. Cases a through d each contain an input error in one record, along with a batch total
computed from that set of records.
For each case (a-d), compute the difference between the correct and erroneous batch totals and explain how this
difference could help identify the cause of the error.
Solution: Differences between the correct transactions column and the batch totals obtained after processing (Case A through D
columns):
(a) (b) (c) (d)
Analysis of these differences:
a. The difference of $9 is evenly divisible by 9, which suggests the possible transposition of adjoining digits in the hundredths
b. A difference of $6,000 represents a discrepancy in only one column, the thousands column. A possible error in transcribing
c. The difference of $8,800.00 is not divisible evenly by 9, which rules out a transposition error. The difference affects multiple
d. The difference of $654.32 is not divisible evenly by 9. However, this amount is equal to one of the entries in the correct
10.5
Answer all of the following multiple-choice questions:
1) An employee who is paid a salary of $50,000 submitted a request to withhold $50 per paycheck in voluntary deductions to
a 401 (K) plan. The next weekly paycheck was for a net amount of $50. The employee was furious. Which of the following
controls would be most effective in detecting this problem prior to distributing the paychecks?
a. Financial total
b. Size check
c. Limit check
d. Reasonableness test
e. Record count
Correct answer: d. Such a test would clearly identify that net pay is unusual. Financial totals and record counts are only useful for
2) A control that checks whether only numeric data is entered in the quantity ordered attribute is called a(n):
a. Compatibility test
b. Numeric test
c. Field check
d. Validity check
e. Check digit verification
3) A sales representative mistakenly entered a nonexistent account number into the system. As a result, the goods were
shipped but the customer was never billed. Which type of control would be most effective in preventing this type of
problem?
a. Turnaround document
b. Completeness check
c. Field check
d. Validity check
e. Check digit verification
4) Which type of batch total would detect the fact that three time cards got lost during processing, which meant that three
employees did not receive a paycheck?
a. Financial total
b. Record count
c. Hash total
d. None of the three would detect the problem
e. All of the three choices would detect the problem
5) Testing whether or not all employees are being paid at least the minimum wage would be an example of a(n):
a. Reasonableness test
b. Sign check
c. Check digit verification
d. Limit check
6) A customer entered the wrong account number on the memo line of the check mailed to the company. Consequently,
another customer’s account was credited for that payment. The most effective way to prevent such problems would be to
use
a. Turnaround documents
b. A validity check of customer account numbers
c. Closed loop verification
d. Check digit verification of customer account numbers
7) Which input control is designed to prevent a buffer overflow attack?
a. Size check
b. Reasonableness test
c. Range check
d. Field check
8) A data entry application control that is designed to ensure that the total debits in a journal entry equal the total credits
is called a __________.
a. Sign check
b. Hash total
c. Reasonableness check
d. Zero-balance check
e. Financial total
9) An application control that compares the amount of an employee’s raise to that employee’s existing salary is
called a(n):
a. Limit check
b. Range test
c. Reasonableness test
d. Check digit verification
e. Size check
10) An organization uses batch processing to generate customer invoices. During the process, the computer sums the
invoice number field for all invoices in the batch and the billing clerk then compares that number to the same total
that the clerk calculated prior to processing. That calculation (the sum of the sales invoice numbers) is a type of
batch total called a:
a. Record count
b. Financial total
c. Hash total
10.6 The ABC Company is considering the following options for its backup plan:
1. Daily full backups:
Time to perform backup = 120 minutes
2. Weekly full backups plus daily incremental backup:
Same time, storage, and restoration as above to make and restore the full
3. Weekly full backups plus daily differential backup:
Same time, storage, and restoration as above to make and restore the full
weekly backup on Saturday, plus
All backups, whether partial or full, must be retained for a full week. Which
approach would you recommend? Why?
Solution: Management must weigh the trade-offs shown below.
Type of Backup
Plan
Time spent weekly to
backup
Storage requirements Time to Restore
Option 1: Full Daily Backup
Option 2: weekly full backup plus daily incremental backup
Backup on
Saturday
last full backup
20+(10+20) +
(10+20) + (10+20) +
(10+20) = up to 140
minutes on Friday
Total 220 Minutes 800 GB 110-230 Minutes
Option 3: weekly full backup plus daily differential backup
Backup
last full backup