WGU C170 PRE-ASSESSMENT DATA MANAGEMENT
APPLICATIONS 2026/2027 | Complete Solution | PA Exam |
Pass Guaranteed - A+ Graded
Section 1: Database Design & Entity-Relationship Modeling (Q1-14)
Q1. A university database tracks students, courses, and enrollments. Each student may
enroll in multiple courses, and each course may have multiple students. Enrollment
records the semester and grade. What is the correct cardinality between Student and
Course?
A. One-to-One
B. One-to-Many
C. Many-to-Many [CORRECT]
D. Zero-to-One
Rationale: A student can take many courses and a course can have many students,
which is a classic many-to-many relationship requiring an associative entity
(Enrollment) to resolve it. A and B are incorrect because they limit participation to single
instances. D is nonsensical in this context.
Correct Answer: C
Q2. In a Crow's Foot ERD notation, what does a circle at the end of a relationship line
indicate?
A. Mandatory participation
,B. Optional participation [CORRECT]
C. Identifying relationship
D. Cardinality of exactly one
Rationale: In Crow's Foot notation, a circle (zero) indicates optional participation
(minimum cardinality of 0), while a perpendicular bar indicates mandatory participation
(minimum of 1). A is incorrect because mandatory is shown by a bar. C refers to
relationship type, not modality. D is incorrect because "exactly one" uses a single bar.
Correct Answer: B
Q3. A database tracks employees and their departments. An employee must belong to
exactly one department, but a department may exist without any employees. What is the
modality from Department to Employee?
A. Mandatory (1)
B. Optional (0) [CORRECT]
C. Mandatory (1..*)
D. Optional (0..1)
Rationale: The modality from Department to Employee is optional (0) because a
department may have zero employees. A is incorrect because departments can exist
without employees. C and D mix cardinality and modality terminology incorrectly.
Correct Answer: B
,Q4. Which of the following is NOT a valid attribute for the entity "Customer" in a retail
database?
A. CustomerID
B. FirstName
C. OrderTotal [CORRECT]
D. EmailAddress
Rationale: OrderTotal is a derived or calculated attribute that belongs to an Order entity,
not a direct attribute of Customer. A is the primary key. B and D are standard descriptive
attributes of a customer.
Correct Answer: C
Q5. In database design, an associative entity is used to resolve which type of
relationship?
A. One-to-One
B. One-to-Many
C. Many-to-Many [CORRECT]
D. Recursive
Rationale: An associative entity (junction table) is required to resolve many-to-many
relationships into two one-to-many relationships. A and B do not require associative
entities. D (recursive) is handled differently with self-referencing keys.
Correct Answer: C
, Q6. A primary key must satisfy which of the following properties?
A. NULL values are permitted
B. Duplicate values are permitted
C. Unique and NOT NULL [CORRECT]
D. Can be a foreign key in the same table
Rationale: A primary key must be unique and cannot contain NULL values per relational
database rules. A and B violate primary key constraints. D describes a self-referencing
foreign key, which is a different concept.
Correct Answer: C
Q7. In an ERD, a weak entity is best described as:
A. An entity with no attributes
B. An entity that cannot be uniquely identified without a relationship to another entity
[CORRECT]
C. An entity with only one attribute
D. An entity with no relationships
Rationale: A weak entity depends on another entity (owner entity) for its unique
identification and uses a partial key. A is incorrect because weak entities have
attributes. C and D are not definitions of weak entities.
Correct Answer: B
APPLICATIONS 2026/2027 | Complete Solution | PA Exam |
Pass Guaranteed - A+ Graded
Section 1: Database Design & Entity-Relationship Modeling (Q1-14)
Q1. A university database tracks students, courses, and enrollments. Each student may
enroll in multiple courses, and each course may have multiple students. Enrollment
records the semester and grade. What is the correct cardinality between Student and
Course?
A. One-to-One
B. One-to-Many
C. Many-to-Many [CORRECT]
D. Zero-to-One
Rationale: A student can take many courses and a course can have many students,
which is a classic many-to-many relationship requiring an associative entity
(Enrollment) to resolve it. A and B are incorrect because they limit participation to single
instances. D is nonsensical in this context.
Correct Answer: C
Q2. In a Crow's Foot ERD notation, what does a circle at the end of a relationship line
indicate?
A. Mandatory participation
,B. Optional participation [CORRECT]
C. Identifying relationship
D. Cardinality of exactly one
Rationale: In Crow's Foot notation, a circle (zero) indicates optional participation
(minimum cardinality of 0), while a perpendicular bar indicates mandatory participation
(minimum of 1). A is incorrect because mandatory is shown by a bar. C refers to
relationship type, not modality. D is incorrect because "exactly one" uses a single bar.
Correct Answer: B
Q3. A database tracks employees and their departments. An employee must belong to
exactly one department, but a department may exist without any employees. What is the
modality from Department to Employee?
A. Mandatory (1)
B. Optional (0) [CORRECT]
C. Mandatory (1..*)
D. Optional (0..1)
Rationale: The modality from Department to Employee is optional (0) because a
department may have zero employees. A is incorrect because departments can exist
without employees. C and D mix cardinality and modality terminology incorrectly.
Correct Answer: B
,Q4. Which of the following is NOT a valid attribute for the entity "Customer" in a retail
database?
A. CustomerID
B. FirstName
C. OrderTotal [CORRECT]
D. EmailAddress
Rationale: OrderTotal is a derived or calculated attribute that belongs to an Order entity,
not a direct attribute of Customer. A is the primary key. B and D are standard descriptive
attributes of a customer.
Correct Answer: C
Q5. In database design, an associative entity is used to resolve which type of
relationship?
A. One-to-One
B. One-to-Many
C. Many-to-Many [CORRECT]
D. Recursive
Rationale: An associative entity (junction table) is required to resolve many-to-many
relationships into two one-to-many relationships. A and B do not require associative
entities. D (recursive) is handled differently with self-referencing keys.
Correct Answer: C
, Q6. A primary key must satisfy which of the following properties?
A. NULL values are permitted
B. Duplicate values are permitted
C. Unique and NOT NULL [CORRECT]
D. Can be a foreign key in the same table
Rationale: A primary key must be unique and cannot contain NULL values per relational
database rules. A and B violate primary key constraints. D describes a self-referencing
foreign key, which is a different concept.
Correct Answer: C
Q7. In an ERD, a weak entity is best described as:
A. An entity with no attributes
B. An entity that cannot be uniquely identified without a relationship to another entity
[CORRECT]
C. An entity with only one attribute
D. An entity with no relationships
Rationale: A weak entity depends on another entity (owner entity) for its unique
identification and uses a partial key. A is incorrect because weak entities have
attributes. C and D are not definitions of weak entities.
Correct Answer: B
