WGU D427 Data Management – Applications OA
Actual Exam 2026/2027 | Questions 1-25 with Verified
Answers | 100% Correct | Pass Guaranteed
SECTION 1: Database Design & Normalization (8 Questions)
Q1 (Screenshot Description): A table screenshot shows:
● Table: CustomerOrders
● Columns: OrderID (PK), CustomerID, CustomerName, OrderDate, ProductID,
ProductName, Quantity, UnitPrice, CustomerEmail
● Sample Data: Multiple rows show same CustomerID with different
CustomerEmail values for same CustomerName.
What normalization problem is demonstrated?
A. No primary key
B. Transitive dependency (3NF violation)
C. Partial key dependency (2NF violation)
D. Repeating groups (1NF violation)
Correct Answer: B
Rationale: Competency: D427.1.3: Apply normalization rules to eliminate data
anomalies.
Analysis: CustomerEmail depends on CustomerID (through CustomerName), creating a
transitive dependency: CustomerID → CustomerName → CustomerEmail.
Violation: Third Normal Form (3NF) requires that non-key attributes depend only on the
primary key, not on other non-key attributes.
Solution: Split into Customers table (CustomerID, CustomerName, CustomerEmail) and
Orders table.
,Business Impact: This causes update anomalies - changing email in one row doesn't
update all rows for same customer.
Q2 (ER Diagram Description): An ER diagram shows:
● Entities: Student, Course, Instructor
● Relationships: Student enrolls in Course (many-to-many), Instructor teaches
Course (one-to-many)
● Attributes: Student has StudentID, Name, Email; Course has CourseID, Title,
Credits; Instructor has InstructorID, Name, Office
What should be the primary key for the enrollment relationship?
A. StudentID
B. CourseID
C. Composite key: StudentID + CourseID
D. Auto-generated EnrollmentID
Correct Answer: C
Rationale: Competency: D427.1.1: Design entity-relationship models.
Analysis: Many-to-many relationships require a junction table to resolve the relationship.
Key Design: The combination of StudentID and CourseID uniquely identifies each
enrollment instance.
Why Not Others: Single attributes would create duplicates (same student enrolled
multiple times or same course with multiple students).
Implementation: This composite key ensures each student-course combination appears
only once.
Q3 (Table Description): A table shows:
● Table: EmployeeProjects
● Columns: EmpID, ProjID, EmpName, ProjName, HoursWorked, Department
● Functional Dependencies: EmpID → EmpName, Department; ProjID →
ProjName; EmpID + ProjID → HoursWorked
, What is the highest normal form this table satisfies?
A. 1NF only
B. 2NF
C. 3NF
D. BCNF
Correct Answer: B
Rationale: Competency: D427.1.2: Analyze functional dependencies for normalization.
Analysis: Primary key is (EmpID, ProjID).
1NF: Satisfied (atomic values).
2NF: Satisfied - no partial dependencies on the composite key.
3NF Violation: EmpName depends on EmpID (part of key), creating transitive
dependency.
Department: Also transitively depends on EmpID.
Solution: Decompose into Employee(EmpID, EmpName, Department) and
EmployeeProject(EmpID, ProjID, HoursWorked).
Q4 (Screenshot Description): A database schema shows:
● Product table: ProductID (PK), ProductName, CategoryID, CategoryName,
SupplierID, SupplierName
● Sample data: ProductID 101 shows "Laptop" with CategoryID 5, CategoryName
"Electronics", SupplierID 10, SupplierName "TechCorp"
What anomaly will occur when updating CategoryName for CategoryID 5?
A. Insertion anomaly
B. Update anomaly
C. Deletion anomaly
D. No anomaly
Correct Answer: B
Rationale: Competency: D427.1.3: Identify data anomalies in unnormalized structures.
Analysis: CategoryName is repeated for all products in the same category.
Actual Exam 2026/2027 | Questions 1-25 with Verified
Answers | 100% Correct | Pass Guaranteed
SECTION 1: Database Design & Normalization (8 Questions)
Q1 (Screenshot Description): A table screenshot shows:
● Table: CustomerOrders
● Columns: OrderID (PK), CustomerID, CustomerName, OrderDate, ProductID,
ProductName, Quantity, UnitPrice, CustomerEmail
● Sample Data: Multiple rows show same CustomerID with different
CustomerEmail values for same CustomerName.
What normalization problem is demonstrated?
A. No primary key
B. Transitive dependency (3NF violation)
C. Partial key dependency (2NF violation)
D. Repeating groups (1NF violation)
Correct Answer: B
Rationale: Competency: D427.1.3: Apply normalization rules to eliminate data
anomalies.
Analysis: CustomerEmail depends on CustomerID (through CustomerName), creating a
transitive dependency: CustomerID → CustomerName → CustomerEmail.
Violation: Third Normal Form (3NF) requires that non-key attributes depend only on the
primary key, not on other non-key attributes.
Solution: Split into Customers table (CustomerID, CustomerName, CustomerEmail) and
Orders table.
,Business Impact: This causes update anomalies - changing email in one row doesn't
update all rows for same customer.
Q2 (ER Diagram Description): An ER diagram shows:
● Entities: Student, Course, Instructor
● Relationships: Student enrolls in Course (many-to-many), Instructor teaches
Course (one-to-many)
● Attributes: Student has StudentID, Name, Email; Course has CourseID, Title,
Credits; Instructor has InstructorID, Name, Office
What should be the primary key for the enrollment relationship?
A. StudentID
B. CourseID
C. Composite key: StudentID + CourseID
D. Auto-generated EnrollmentID
Correct Answer: C
Rationale: Competency: D427.1.1: Design entity-relationship models.
Analysis: Many-to-many relationships require a junction table to resolve the relationship.
Key Design: The combination of StudentID and CourseID uniquely identifies each
enrollment instance.
Why Not Others: Single attributes would create duplicates (same student enrolled
multiple times or same course with multiple students).
Implementation: This composite key ensures each student-course combination appears
only once.
Q3 (Table Description): A table shows:
● Table: EmployeeProjects
● Columns: EmpID, ProjID, EmpName, ProjName, HoursWorked, Department
● Functional Dependencies: EmpID → EmpName, Department; ProjID →
ProjName; EmpID + ProjID → HoursWorked
, What is the highest normal form this table satisfies?
A. 1NF only
B. 2NF
C. 3NF
D. BCNF
Correct Answer: B
Rationale: Competency: D427.1.2: Analyze functional dependencies for normalization.
Analysis: Primary key is (EmpID, ProjID).
1NF: Satisfied (atomic values).
2NF: Satisfied - no partial dependencies on the composite key.
3NF Violation: EmpName depends on EmpID (part of key), creating transitive
dependency.
Department: Also transitively depends on EmpID.
Solution: Decompose into Employee(EmpID, EmpName, Department) and
EmployeeProject(EmpID, ProjID, HoursWorked).
Q4 (Screenshot Description): A database schema shows:
● Product table: ProductID (PK), ProductName, CategoryID, CategoryName,
SupplierID, SupplierName
● Sample data: ProductID 101 shows "Laptop" with CategoryID 5, CategoryName
"Electronics", SupplierID 10, SupplierName "TechCorp"
What anomaly will occur when updating CategoryName for CategoryID 5?
A. Insertion anomaly
B. Update anomaly
C. Deletion anomaly
D. No anomaly
Correct Answer: B
Rationale: Competency: D427.1.3: Identify data anomalies in unnormalized structures.
Analysis: CategoryName is repeated for all products in the same category.
