WGU C784 Applied Healthcare Statistics OA &
PA | Descriptive Stats, Probability, Hypothesis
Testing & Data Interpretation — Practice
Questions
1. Which number system includes all positive whole numbers, their negatives,
and zero?
A) Natural numbers
B) Whole numbers
C) Integers
D) Rational numbers
Answer: C) Integers
Rationale: Integers include all positive and negative whole numbers and zero.
Natural numbers are positive only (1,2,3...), and whole numbers are non-negative
(0,1,2...). Rational numbers include fractions and decimals.
2. Which of the following is an irrational number?
A) 0.75
B) √16
C) π (pi)
D) -5
Answer: C) π (pi)
Rationale: Irrational numbers cannot be expressed as a simple fraction. π ≈
3.14159... is non-terminating and non-repeating. 0.75 = 3/4, √16 = 4, and -5 are all
rational.
3. What is the absolute value of -12?
A) -12
,B) 0
C) 12
D) 144
Answer: C) 12
Rationale: Absolute value represents the distance from zero on a number line,
always non-negative. |-12| = 12.
4. Which number is a prime number?
A) 1
B) 4
C) 9
D) 7
Answer: D) 7
Rationale: A prime number has exactly two distinct positive divisors: 1 and itself. 7
is only divisible by 1 and 7. 1 is neither prime nor composite; 4 and 9 are
composite.
5. Order the following from least to greatest: -3, 0, 2, -1, 5
A) -3, -1, 0, 2, 5
B) -1, -3, 0, 2, 5
C) 5, 2, 0, -1, -3
D) -3, 0, -1, 2, 5
Answer: A) -3, -1, 0, 2, 5
Rationale: On a number line, numbers increase from left to right. Negative
numbers are smaller than zero, and -3 is less than -1.
6. Which property is demonstrated by: (3 + 4) + 5 = 3 + (4 + 5)?
A) Commutative property
B) Associative property
,C) Distributive property
D) Identity property
Answer: B) Associative property
Rationale: The associative property states that the grouping of numbers in
addition or multiplication does not change the sum or product. The numbers are
regrouped but not reordered.
7. What is the reciprocal of 3/8?
A) -3/8
B) 8/3
C) 3/8
D) 1
Answer: B) 8/3
Rationale: The reciprocal of a fraction is obtained by swapping the numerator and
denominator. The reciprocal of 3/8 is 8/3.
8. Which of the following is a rational number?
A) √2
B) √3
C) 0.333... (repeating)
D) π
Answer: C) 0.333... (repeating)
Rationale: Repeating decimals are rational because they can be expressed as
fractions (0.333... = 1/3). √2, √3, and π are irrational.
9. What is 5³ equal to?
A) 15
B) 125
, C) 25
D) 8
Answer: B) 125
Rationale: 5³ means 5 × 5 × 5 = 125. This is exponential notation.
10. The number 0.00075 in scientific notation is:
A) 7.5 × 10⁻⁴
B) 7.5 × 10⁴
C) 75 × 10⁻⁵
D) 0.75 × 10⁻³
Answer: A) 7.5 × 10⁻⁴
Rationale: Scientific notation requires a number between 1 and 10 multiplied by a
power of 10. 0.00075 = 7.5 × 10⁻⁴ (move decimal 4 places right).
SECTION 2: FRACTIONS, DECIMALS, & PERCENTAGES (Questions 11–20)
11. Convert 0.625 to a fraction in simplest form.
A) 5/8
B) 3/5
C) 7/8
D) 2/3
Answer: A) 5/8
Rationale: 0.625 = 625/1000. Divide numerator and denominator by 125 → 5/8.
12. What is 45% as a decimal?
A) 0.045
B) 4.5
C) 0.45
D) 45.0
PA | Descriptive Stats, Probability, Hypothesis
Testing & Data Interpretation — Practice
Questions
1. Which number system includes all positive whole numbers, their negatives,
and zero?
A) Natural numbers
B) Whole numbers
C) Integers
D) Rational numbers
Answer: C) Integers
Rationale: Integers include all positive and negative whole numbers and zero.
Natural numbers are positive only (1,2,3...), and whole numbers are non-negative
(0,1,2...). Rational numbers include fractions and decimals.
2. Which of the following is an irrational number?
A) 0.75
B) √16
C) π (pi)
D) -5
Answer: C) π (pi)
Rationale: Irrational numbers cannot be expressed as a simple fraction. π ≈
3.14159... is non-terminating and non-repeating. 0.75 = 3/4, √16 = 4, and -5 are all
rational.
3. What is the absolute value of -12?
A) -12
,B) 0
C) 12
D) 144
Answer: C) 12
Rationale: Absolute value represents the distance from zero on a number line,
always non-negative. |-12| = 12.
4. Which number is a prime number?
A) 1
B) 4
C) 9
D) 7
Answer: D) 7
Rationale: A prime number has exactly two distinct positive divisors: 1 and itself. 7
is only divisible by 1 and 7. 1 is neither prime nor composite; 4 and 9 are
composite.
5. Order the following from least to greatest: -3, 0, 2, -1, 5
A) -3, -1, 0, 2, 5
B) -1, -3, 0, 2, 5
C) 5, 2, 0, -1, -3
D) -3, 0, -1, 2, 5
Answer: A) -3, -1, 0, 2, 5
Rationale: On a number line, numbers increase from left to right. Negative
numbers are smaller than zero, and -3 is less than -1.
6. Which property is demonstrated by: (3 + 4) + 5 = 3 + (4 + 5)?
A) Commutative property
B) Associative property
,C) Distributive property
D) Identity property
Answer: B) Associative property
Rationale: The associative property states that the grouping of numbers in
addition or multiplication does not change the sum or product. The numbers are
regrouped but not reordered.
7. What is the reciprocal of 3/8?
A) -3/8
B) 8/3
C) 3/8
D) 1
Answer: B) 8/3
Rationale: The reciprocal of a fraction is obtained by swapping the numerator and
denominator. The reciprocal of 3/8 is 8/3.
8. Which of the following is a rational number?
A) √2
B) √3
C) 0.333... (repeating)
D) π
Answer: C) 0.333... (repeating)
Rationale: Repeating decimals are rational because they can be expressed as
fractions (0.333... = 1/3). √2, √3, and π are irrational.
9. What is 5³ equal to?
A) 15
B) 125
, C) 25
D) 8
Answer: B) 125
Rationale: 5³ means 5 × 5 × 5 = 125. This is exponential notation.
10. The number 0.00075 in scientific notation is:
A) 7.5 × 10⁻⁴
B) 7.5 × 10⁴
C) 75 × 10⁻⁵
D) 0.75 × 10⁻³
Answer: A) 7.5 × 10⁻⁴
Rationale: Scientific notation requires a number between 1 and 10 multiplied by a
power of 10. 0.00075 = 7.5 × 10⁻⁴ (move decimal 4 places right).
SECTION 2: FRACTIONS, DECIMALS, & PERCENTAGES (Questions 11–20)
11. Convert 0.625 to a fraction in simplest form.
A) 5/8
B) 3/5
C) 7/8
D) 2/3
Answer: A) 5/8
Rationale: 0.625 = 625/1000. Divide numerator and denominator by 125 → 5/8.
12. What is 45% as a decimal?
A) 0.045
B) 4.5
C) 0.45
D) 45.0
