WGU C992 Database and Analytic Geometry
Exam Review with Complete Solutions
1. What is a foreign key used for in a database table?
A) To uniquely identify rows
B) To reference a primary key in another table
C) To store temporary data
D) To sort data
Answer: B
A foreign key links one table to another by referencing the primary key of the related table. It
enforces referential integrity, preventing invalid data entry. WGU often tests understanding of
relational connections between tables.
2. Which SQL clause filters rows based on a condition?
A) GROUP BY
B) ORDER BY
C) WHERE
D) HAVING
Answer: C
The WHERE clause filters records before grouping or aggregation. It specifies conditions that
must be met for rows to be included in the result. WHERE applies to individual rows, not
groups.
3. Which triangle has all angles less than 90°?
A) Right triangle
B) Obtuse triangle
C) Acute triangle
D) Scalene triangle
Answer: C
An acute triangle has three angles all less than 90 degrees. Its side lengths can vary, but no angle
reaches or exceeds a right angle. Acute triangles are common in coordinate proofs.
4. What does the HAVING clause do in SQL?
A) Filters individual rows
B) Filters groups after aggregation
C) Joins tables
D) Orders results
Answer: B
HAVING filters groups created by GROUP BY. Unlike WHERE, it operates on aggregate
results, such as totals or averages. WGU scenarios often ask when to use HAVING versus
WHERE.
,5. How is the Pythagorean theorem applied in coordinate geometry?
A) To find slopes
B) To calculate distances between points
C) To find midpoints
D) To determine angles
Answer: B
The distance formula derives from the Pythagorean theorem. Horizontal and vertical differences
form the triangle legs, and the distance is the hypotenuse. This method confirms distances in the
coordinate plane.
6. Which JOIN returns all rows from the left table, and matching rows from the right?
A) INNER JOIN
B) LEFT JOIN
C) RIGHT JOIN
D) FULL JOIN
Answer: B
A LEFT JOIN returns all rows from the left table regardless of match, filling NULLs when the
right table has no match. This is useful when one table contains mandatory records. WGU often
tests this in scenario questions.
7. Triangle with vertices (2,3), (5,3), (2,7) is:
A) Equilateral
B) Isosceles
C) Right
D) Scalene
Answer: C
Slopes: (2,3)–(5,3)=0, (2,3)–(2,7)=undefined → perpendicular sides → right triangle. The
Pythagorean theorem can also confirm the 90° angle.
8. Which aggregate function returns the largest value in a column?
A) SUM
B) MAX
C) AVG
D) COUNT
Answer: B
MAX returns the highest value in a dataset. It ignores NULLs and is often used with GROUP
BY to find top values per group. WGU sometimes combines MAX with HAVING for filtered
aggregates.
9. What is an equilateral triangle?
A) Triangle with two equal sides
B) Triangle with all equal sides and angles
C) Triangle with a right angle
D) Triangle with all sides unequal
Answer: B
, An equilateral triangle has three equal sides and three equal angles of 60 degrees. It is a special
case of an isosceles triangle. Coordinates can confirm equality by distance formula.
10. Which SQL statement removes all rows from a table without logging individual row
deletions?
A) DELETE
B) TRUNCATE
C) DROP
D) UPDATE
Answer: B
TRUNCATE removes all rows efficiently and resets identity columns. DELETE removes rows
individually and logs each action. WGU scenarios may ask the difference between DELETE and
TRUNCATE.
11. Midpoint of points (−2,1) and (4,5) is:
A) (1,3)
B) (0,3)
C) (2,2)
D) (−1,3)
Answer: A
Midpoint = ((−2+4)/2, (1+5)/2) = (1,3). Averaging coordinates gives the exact center between
two points.
12. What does a negative correlation in a dataset indicate?
A) Both variables increase together
B) One variable increases while the other decreases
C) No relationship exists
D) Variables are constant
Answer: B
Negative correlation means as one variable rises, the other falls. It is quantified with correlation
coefficients between −1 and 0. This concept is important in data analysis scenarios.
13. Which line is horizontal through points (1,4) and (5,4)?
A) y = 4
B) x = 1
C) y = −4
D) x = 4
Answer: A
Horizontal lines have constant y-values. The slope is zero, showing no vertical change.
Horizontal lines run parallel to the x-axis.
14. What does the DISTINCT keyword do in SQL?
A) Joins tables
B) Eliminates duplicate rows
C) Aggregates data
D) Sorts rows
Exam Review with Complete Solutions
1. What is a foreign key used for in a database table?
A) To uniquely identify rows
B) To reference a primary key in another table
C) To store temporary data
D) To sort data
Answer: B
A foreign key links one table to another by referencing the primary key of the related table. It
enforces referential integrity, preventing invalid data entry. WGU often tests understanding of
relational connections between tables.
2. Which SQL clause filters rows based on a condition?
A) GROUP BY
B) ORDER BY
C) WHERE
D) HAVING
Answer: C
The WHERE clause filters records before grouping or aggregation. It specifies conditions that
must be met for rows to be included in the result. WHERE applies to individual rows, not
groups.
3. Which triangle has all angles less than 90°?
A) Right triangle
B) Obtuse triangle
C) Acute triangle
D) Scalene triangle
Answer: C
An acute triangle has three angles all less than 90 degrees. Its side lengths can vary, but no angle
reaches or exceeds a right angle. Acute triangles are common in coordinate proofs.
4. What does the HAVING clause do in SQL?
A) Filters individual rows
B) Filters groups after aggregation
C) Joins tables
D) Orders results
Answer: B
HAVING filters groups created by GROUP BY. Unlike WHERE, it operates on aggregate
results, such as totals or averages. WGU scenarios often ask when to use HAVING versus
WHERE.
,5. How is the Pythagorean theorem applied in coordinate geometry?
A) To find slopes
B) To calculate distances between points
C) To find midpoints
D) To determine angles
Answer: B
The distance formula derives from the Pythagorean theorem. Horizontal and vertical differences
form the triangle legs, and the distance is the hypotenuse. This method confirms distances in the
coordinate plane.
6. Which JOIN returns all rows from the left table, and matching rows from the right?
A) INNER JOIN
B) LEFT JOIN
C) RIGHT JOIN
D) FULL JOIN
Answer: B
A LEFT JOIN returns all rows from the left table regardless of match, filling NULLs when the
right table has no match. This is useful when one table contains mandatory records. WGU often
tests this in scenario questions.
7. Triangle with vertices (2,3), (5,3), (2,7) is:
A) Equilateral
B) Isosceles
C) Right
D) Scalene
Answer: C
Slopes: (2,3)–(5,3)=0, (2,3)–(2,7)=undefined → perpendicular sides → right triangle. The
Pythagorean theorem can also confirm the 90° angle.
8. Which aggregate function returns the largest value in a column?
A) SUM
B) MAX
C) AVG
D) COUNT
Answer: B
MAX returns the highest value in a dataset. It ignores NULLs and is often used with GROUP
BY to find top values per group. WGU sometimes combines MAX with HAVING for filtered
aggregates.
9. What is an equilateral triangle?
A) Triangle with two equal sides
B) Triangle with all equal sides and angles
C) Triangle with a right angle
D) Triangle with all sides unequal
Answer: B
, An equilateral triangle has three equal sides and three equal angles of 60 degrees. It is a special
case of an isosceles triangle. Coordinates can confirm equality by distance formula.
10. Which SQL statement removes all rows from a table without logging individual row
deletions?
A) DELETE
B) TRUNCATE
C) DROP
D) UPDATE
Answer: B
TRUNCATE removes all rows efficiently and resets identity columns. DELETE removes rows
individually and logs each action. WGU scenarios may ask the difference between DELETE and
TRUNCATE.
11. Midpoint of points (−2,1) and (4,5) is:
A) (1,3)
B) (0,3)
C) (2,2)
D) (−1,3)
Answer: A
Midpoint = ((−2+4)/2, (1+5)/2) = (1,3). Averaging coordinates gives the exact center between
two points.
12. What does a negative correlation in a dataset indicate?
A) Both variables increase together
B) One variable increases while the other decreases
C) No relationship exists
D) Variables are constant
Answer: B
Negative correlation means as one variable rises, the other falls. It is quantified with correlation
coefficients between −1 and 0. This concept is important in data analysis scenarios.
13. Which line is horizontal through points (1,4) and (5,4)?
A) y = 4
B) x = 1
C) y = −4
D) x = 4
Answer: A
Horizontal lines have constant y-values. The slope is zero, showing no vertical change.
Horizontal lines run parallel to the x-axis.
14. What does the DISTINCT keyword do in SQL?
A) Joins tables
B) Eliminates duplicate rows
C) Aggregates data
D) Sorts rows
