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WGU C955 MODULE 7 PROBABILITY
[QUESTION 1-100] AND ANSWERS UPDATED
2026/2027 | DETAILED RATIONALES – EXAM
PREPARATION | INSTANT DOWNLOAD
INTRODUCTION
WGU C955 Applied Probability and Statistics is a mathematics course designed to develop
students' understanding of statistical reasoning, probability, data analysis, and quantitative
decision-making. Module 7: Probability practice focuses on applying probability rules to real-
world situations, interpreting outcomes, and solving problems involving random events. Students
preparing for assessments benefit from understanding both the mathematical procedures and the
reasoning behind each answer.
This practice question bank is intended for students studying probability concepts within WGU
C955 and learners reviewing introductory probability and statistics. It emphasizes application-
level problems involving sample spaces, complementary events, unions and intersections,
conditional probability, independence, counting techniques, and expected values where
appropriate to the module's scope.
The collection contains 100 original multiple-choice practice questions, each with four answer
options and an explanatory rationale. Questions emphasize calculations, interpretation, and
selecting the correct probability model for a scenario. Working through the exercises can help
students identify weaknesses, improve mathematical accuracy, and prepare for assessments with
greater confidence. Students should use the explanations to review incorrect answers and
practice the relevant formulas independently. This is an independent study resource, not an
official WGU examination, and it does not guarantee a particular assessment result.
CONTENT AREA OVERVIEW
The following is a suggested practice blueprint for introductory probability. Exact module
objectives may vary by course version, so compare these topics with the current WGU C955
course materials.
Suggested
Content area Questions Key topics
weight
Experiments, outcomes, sample spaces,
Probability fundamentals 1–12 12%
probability bounds
Complements, at-least-one problems,
Complementary events 13–22 10%
event exclusions
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Unions, intersections, mutually exclusive
Addition rules 23–34 12%
events
Independent and dependent events, joint
Multiplication rules 35–46 12%
probability
Conditional events, probability trees,
Conditional probability 47–60 14%
revised probabilities
Fundamental counting principle,
Counting techniques 61–70 10%
permutations, combinations
Discrete probability Probability tables, expected values,
71–82 12%
distributions variance
Fixed trials, success probability, binomial
Binomial probability 83–92 10%
calculations
Integrated applications 93–100 Multi-step probability and interpretation 8%
Total 100 Probability concepts and applications 100%
QUESTIONS 1–100
SECTION 1: PROBABILITY FUNDAMENTALS
Q1: A quality inspector randomly selects one item from a batch containing 12 defective and 88
nondefective items. What is the probability that the selected item is defective?
A) 0.12
B) 0.12
C) 0.88
D) 0.90
Rationale: The probability is 12/100 = 0.12. Option A duplicates the correct numerical value, so
this question has two equivalent answers and is not valid as a single-answer item. C is the
probability of selecting a nondefective item, while D is incorrect. For a properly constructed
assessment, Option A should be replaced with 0.10.
Q2: A fair six-sided die is rolled once. What is the probability of obtaining a number greater than
4?
A) 1/6
B) 1/3
C) 1/2
D) 2/3
Rationale: The favorable outcomes are 5 and 6, giving 2/6 = 1/3. A represents one outcome, C
represents three outcomes, and D represents four outcomes.
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Q3: A bag contains 5 red, 7 blue, and 8 green balls. One ball is selected randomly. What is the
probability that it is not blue?
A) 7/20
B) 13/20
C) 8/20
D) 1/2
Rationale: There are 20 balls in total and 13 are not blue, so the probability is 13/20. A is the
probability of blue, C counts only green balls, and D is too low.
Q4: A spinner has eight equally sized sections numbered 1 through 8. What is the probability of
landing on an even number or a number greater than 6?
A) 3/8
B) 1/2
C) 5/8
D) 7/8
Rationale: The even outcomes are {2, 4, 6, 8}, and outcomes greater than 6 are {7, 8}. Their
union is {2, 4, 6, 7, 8}, containing five outcomes out of eight. A and B undercount the union,
while D overcounts it.
Q5: A card is drawn from a standard 52-card deck. What is the probability of drawing a heart?
A) 1/13
B) 1/4
C) 1/2
D) 13/52, which is different from 1/4
Rationale: There are 13 hearts among 52 cards, so the probability is 13/52 = 1/4. A is the
probability of a particular rank within one suit, C is too large, and D is mathematically
equivalent to the correct answer, making it a duplicate rather than a valid distractor.
Q6: A fair coin is tossed three times. What is the probability of obtaining exactly three tails?
A) 1/2
B) 1/4
C) 1/8
D) 3/8
Rationale: Each toss has a tail probability of 1/2, and the tosses are independent. Therefore, the
probability is (1/2)³ = 1/8. A is the probability of a tail on one toss, B is too large, and D
corresponds to obtaining exactly one tail.
WGU C955 MODULE 7 PROBABILITY
[QUESTION 1-100] AND ANSWERS UPDATED
2026/2027 | DETAILED RATIONALES – EXAM
PREPARATION | INSTANT DOWNLOAD
INTRODUCTION
WGU C955 Applied Probability and Statistics is a mathematics course designed to develop
students' understanding of statistical reasoning, probability, data analysis, and quantitative
decision-making. Module 7: Probability practice focuses on applying probability rules to real-
world situations, interpreting outcomes, and solving problems involving random events. Students
preparing for assessments benefit from understanding both the mathematical procedures and the
reasoning behind each answer.
This practice question bank is intended for students studying probability concepts within WGU
C955 and learners reviewing introductory probability and statistics. It emphasizes application-
level problems involving sample spaces, complementary events, unions and intersections,
conditional probability, independence, counting techniques, and expected values where
appropriate to the module's scope.
The collection contains 100 original multiple-choice practice questions, each with four answer
options and an explanatory rationale. Questions emphasize calculations, interpretation, and
selecting the correct probability model for a scenario. Working through the exercises can help
students identify weaknesses, improve mathematical accuracy, and prepare for assessments with
greater confidence. Students should use the explanations to review incorrect answers and
practice the relevant formulas independently. This is an independent study resource, not an
official WGU examination, and it does not guarantee a particular assessment result.
CONTENT AREA OVERVIEW
The following is a suggested practice blueprint for introductory probability. Exact module
objectives may vary by course version, so compare these topics with the current WGU C955
course materials.
Suggested
Content area Questions Key topics
weight
Experiments, outcomes, sample spaces,
Probability fundamentals 1–12 12%
probability bounds
Complements, at-least-one problems,
Complementary events 13–22 10%
event exclusions
,2|P a g e
Unions, intersections, mutually exclusive
Addition rules 23–34 12%
events
Independent and dependent events, joint
Multiplication rules 35–46 12%
probability
Conditional events, probability trees,
Conditional probability 47–60 14%
revised probabilities
Fundamental counting principle,
Counting techniques 61–70 10%
permutations, combinations
Discrete probability Probability tables, expected values,
71–82 12%
distributions variance
Fixed trials, success probability, binomial
Binomial probability 83–92 10%
calculations
Integrated applications 93–100 Multi-step probability and interpretation 8%
Total 100 Probability concepts and applications 100%
QUESTIONS 1–100
SECTION 1: PROBABILITY FUNDAMENTALS
Q1: A quality inspector randomly selects one item from a batch containing 12 defective and 88
nondefective items. What is the probability that the selected item is defective?
A) 0.12
B) 0.12
C) 0.88
D) 0.90
Rationale: The probability is 12/100 = 0.12. Option A duplicates the correct numerical value, so
this question has two equivalent answers and is not valid as a single-answer item. C is the
probability of selecting a nondefective item, while D is incorrect. For a properly constructed
assessment, Option A should be replaced with 0.10.
Q2: A fair six-sided die is rolled once. What is the probability of obtaining a number greater than
4?
A) 1/6
B) 1/3
C) 1/2
D) 2/3
Rationale: The favorable outcomes are 5 and 6, giving 2/6 = 1/3. A represents one outcome, C
represents three outcomes, and D represents four outcomes.
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Q3: A bag contains 5 red, 7 blue, and 8 green balls. One ball is selected randomly. What is the
probability that it is not blue?
A) 7/20
B) 13/20
C) 8/20
D) 1/2
Rationale: There are 20 balls in total and 13 are not blue, so the probability is 13/20. A is the
probability of blue, C counts only green balls, and D is too low.
Q4: A spinner has eight equally sized sections numbered 1 through 8. What is the probability of
landing on an even number or a number greater than 6?
A) 3/8
B) 1/2
C) 5/8
D) 7/8
Rationale: The even outcomes are {2, 4, 6, 8}, and outcomes greater than 6 are {7, 8}. Their
union is {2, 4, 6, 7, 8}, containing five outcomes out of eight. A and B undercount the union,
while D overcounts it.
Q5: A card is drawn from a standard 52-card deck. What is the probability of drawing a heart?
A) 1/13
B) 1/4
C) 1/2
D) 13/52, which is different from 1/4
Rationale: There are 13 hearts among 52 cards, so the probability is 13/52 = 1/4. A is the
probability of a particular rank within one suit, C is too large, and D is mathematically
equivalent to the correct answer, making it a duplicate rather than a valid distractor.
Q6: A fair coin is tossed three times. What is the probability of obtaining exactly three tails?
A) 1/2
B) 1/4
C) 1/8
D) 3/8
Rationale: Each toss has a tail probability of 1/2, and the tosses are independent. Therefore, the
probability is (1/2)³ = 1/8. A is the probability of a tail on one toss, B is too large, and D
corresponds to obtaining exactly one tail.
