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WGU C784 Applied Healthcare
Statistics OA & PA Exam Study
Guide 2026
Prepare for WGU C784 Applied Healthcare Statistics
with this comprehensive study guide covering all 7
competencies: basic numeracy, fractions, decimals,
percentages, algebra, descriptive statistics, correlation,
regression, and probability. Includes practice questions
with detailed rationales, verified answers, and key
concepts for the objective assessment. Topics include
order of operations, GCF/LCM, unit conversions, normal
distribution, confidence intervals, hypothesis testing, and
healthcare-focused statistical applications. Updated for
2026.
Q1. Evaluate the following expression using the order of operations: 4 + 7 x (6 - 3)^2
A. 67
B. 99
C. 121
D. 45
Answer: A. 67
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Rationale: Following PEMDAS, first solve the parentheses: (6 - 3) = 3. Then
evaluate the exponent: 3^2 = 9. Next, multiply: 7 x 9 = 63. Finally, add: 4 + 63
= 67. Options B, C, and D result from common errors such as squaring before
subtracting, multiplying before resolving the exponent, or adding before
multiplying.
Q2. Simplify the following fraction: 3/14 - 1/7
A. 2/7
B. 1/14
C. 2/14
D. 1/7
Answer: B. 1/14
Rationale: To subtract fractions, find a common denominator. The least
common denominator of 14 and 7 is 14. Rewrite 1/7 as 2/14. Then subtract:
3/14 - 2/14 = 1/14. Option A is incorrect because it does not use a common
denominator. Option C is the unsimplified intermediate step before subtracting.
Option D results from incorrectly simplifying 2/14.
Q3. A medication dosage increases from 180 mg to 220 mg. What is the percent
increase?
A. 18.2%
B. 20.0%
C. 22.2%
D. 40.0%
Answer: C. 22.2%
Rationale: Percent increase = (change / original) x 100. The change is 220 - 180
= 40 mg. Divide 40 by the original value of 180: 40/180 = 0.2222. Multiply by
100 to get 22.2%. Option D is the raw difference, not a percentage. Option B
would be correct only if the original were 200. Option A results from dividing by
the new value instead of the original.
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Q4. From the following set of numbers, what is the sum of all whole numbers? {10,
2.5, -4, -4.5, 5}
A. 11
B. 15
C. 9
D. 6
Answer: B. 15
Rationale: Whole numbers are non-negative integers including zero. In this set,
the whole numbers are 10 and 5. Their sum is 10 + 5 = 15. The values 2.5 and -
4.5 are not whole numbers because they are decimals. The value -4 is an integer
but not a whole number because it is negative. Option A results from adding -4
incorrectly. Option C results from including -4 and excluding 10. Option D
results from excluding 10 and adding only 5 and the absolute value of other
numbers.
Q5. What is the greatest common factor of 132 and 11?
A. 1
B. 11
C. 22
D. 132
Answer: B. 11
Rationale: The greatest common factor is the largest number that divides evenly
into both values. Since 132 divided by 11 equals 12 with no remainder, and 11
divided by 11 equals 1, the GCF is 11. Option A would be correct only if the
numbers shared no common factors. Option C is incorrect because 22 does not
divide evenly into 11. Option D is incorrect because 132 does not divide evenly
into 11.
Q6. From the set {3.3, -2.3, -16, 25}, what are the square roots of the whole number?
A. 3.3 and -2.3
B. 4 and -4
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C. 5 and -5
D. 16 and -16
Answer: C. 5 and -5
Rationale: The only whole number in the set is 25. The square root of 25 is 5
because 5 x 5 = 25. Since both positive and negative values square to a positive
number, -5 is also a square root: (-5) x (-5) = 25. Option A lists decimals from
the set, not square roots. Option B is the square root of 16, which is not a whole
number in the set. Option D confuses the square root with the square.
Q7. An IV drip is running at a rate of 4.5 mL per minute. What is the equivalent rate
in milliliters per hour?
A. 45 mL/hour
B. 270 mL/hour
C. 150 mL/hour
D. 360 mL/hour
Answer: B. 270 mL/hour
Rationale: There are 60 minutes in one hour. Multiply the rate by 60: 4.5 x 60 =
270 mL/hour. Option A results from multiplying by 10 instead of 60. Option C
results from an incorrect conversion factor. Option D results from multiplying 6
x 60 instead of 4.5 x 60.
Q8. Evaluate the following expression: + 2 x 5 - 4
A. 12
B. 16
C. 24
D. 10
Answer: B. 16
Rationale: Following PEMDAS, perform division and multiplication from left to
right before addition and subtraction. First, = 6. Then, 2 x 5 = 10. The
expression becomes 6 + 10 - 4. Adding gives 16, then subtracting 4 gives 12.
WGU C784 Applied Healthcare
Statistics OA & PA Exam Study
Guide 2026
Prepare for WGU C784 Applied Healthcare Statistics
with this comprehensive study guide covering all 7
competencies: basic numeracy, fractions, decimals,
percentages, algebra, descriptive statistics, correlation,
regression, and probability. Includes practice questions
with detailed rationales, verified answers, and key
concepts for the objective assessment. Topics include
order of operations, GCF/LCM, unit conversions, normal
distribution, confidence intervals, hypothesis testing, and
healthcare-focused statistical applications. Updated for
2026.
Q1. Evaluate the following expression using the order of operations: 4 + 7 x (6 - 3)^2
A. 67
B. 99
C. 121
D. 45
Answer: A. 67
,2|Page
Rationale: Following PEMDAS, first solve the parentheses: (6 - 3) = 3. Then
evaluate the exponent: 3^2 = 9. Next, multiply: 7 x 9 = 63. Finally, add: 4 + 63
= 67. Options B, C, and D result from common errors such as squaring before
subtracting, multiplying before resolving the exponent, or adding before
multiplying.
Q2. Simplify the following fraction: 3/14 - 1/7
A. 2/7
B. 1/14
C. 2/14
D. 1/7
Answer: B. 1/14
Rationale: To subtract fractions, find a common denominator. The least
common denominator of 14 and 7 is 14. Rewrite 1/7 as 2/14. Then subtract:
3/14 - 2/14 = 1/14. Option A is incorrect because it does not use a common
denominator. Option C is the unsimplified intermediate step before subtracting.
Option D results from incorrectly simplifying 2/14.
Q3. A medication dosage increases from 180 mg to 220 mg. What is the percent
increase?
A. 18.2%
B. 20.0%
C. 22.2%
D. 40.0%
Answer: C. 22.2%
Rationale: Percent increase = (change / original) x 100. The change is 220 - 180
= 40 mg. Divide 40 by the original value of 180: 40/180 = 0.2222. Multiply by
100 to get 22.2%. Option D is the raw difference, not a percentage. Option B
would be correct only if the original were 200. Option A results from dividing by
the new value instead of the original.
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Q4. From the following set of numbers, what is the sum of all whole numbers? {10,
2.5, -4, -4.5, 5}
A. 11
B. 15
C. 9
D. 6
Answer: B. 15
Rationale: Whole numbers are non-negative integers including zero. In this set,
the whole numbers are 10 and 5. Their sum is 10 + 5 = 15. The values 2.5 and -
4.5 are not whole numbers because they are decimals. The value -4 is an integer
but not a whole number because it is negative. Option A results from adding -4
incorrectly. Option C results from including -4 and excluding 10. Option D
results from excluding 10 and adding only 5 and the absolute value of other
numbers.
Q5. What is the greatest common factor of 132 and 11?
A. 1
B. 11
C. 22
D. 132
Answer: B. 11
Rationale: The greatest common factor is the largest number that divides evenly
into both values. Since 132 divided by 11 equals 12 with no remainder, and 11
divided by 11 equals 1, the GCF is 11. Option A would be correct only if the
numbers shared no common factors. Option C is incorrect because 22 does not
divide evenly into 11. Option D is incorrect because 132 does not divide evenly
into 11.
Q6. From the set {3.3, -2.3, -16, 25}, what are the square roots of the whole number?
A. 3.3 and -2.3
B. 4 and -4
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C. 5 and -5
D. 16 and -16
Answer: C. 5 and -5
Rationale: The only whole number in the set is 25. The square root of 25 is 5
because 5 x 5 = 25. Since both positive and negative values square to a positive
number, -5 is also a square root: (-5) x (-5) = 25. Option A lists decimals from
the set, not square roots. Option B is the square root of 16, which is not a whole
number in the set. Option D confuses the square root with the square.
Q7. An IV drip is running at a rate of 4.5 mL per minute. What is the equivalent rate
in milliliters per hour?
A. 45 mL/hour
B. 270 mL/hour
C. 150 mL/hour
D. 360 mL/hour
Answer: B. 270 mL/hour
Rationale: There are 60 minutes in one hour. Multiply the rate by 60: 4.5 x 60 =
270 mL/hour. Option A results from multiplying by 10 instead of 60. Option C
results from an incorrect conversion factor. Option D results from multiplying 6
x 60 instead of 4.5 x 60.
Q8. Evaluate the following expression: + 2 x 5 - 4
A. 12
B. 16
C. 24
D. 10
Answer: B. 16
Rationale: Following PEMDAS, perform division and multiplication from left to
right before addition and subtraction. First, = 6. Then, 2 x 5 = 10. The
expression becomes 6 + 10 - 4. Adding gives 16, then subtracting 4 gives 12.
