WGU C955 - MODULE 7: PROBABILITY
EXACT EXAM 2026/ QUESTIONS AND
VERIFIED ANSWERS GRADED A+
10 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Apply the axioms of probability to compute probabilities of events, including complements, unions, and
intersections
2 Compute conditional probabilities and determine independence of events
3 Apply Bayes' theorem to update probabilities given new information
4 Calculate expected value and variance for discrete and continuous random variables
5 Identify and apply properties of binomial, Poisson, and normal distributions to solve problems
6 WGU C955
7 Module 7
8 Probability Exact Exam 2026
9 Questions and Verified Answers Graded A+
10 Foundations of Probability and Statistics
ABSTRACT
This study document brings together 10 carefully worded exam questions drawn from WGU C955 -
Module 7: Probability Exact Exam 2026/ Questions and Verified Answers Graded A+, with the
strongest emphasis placed on Apply the axioms of probability to compute probabilities of events,
including complements, unions, and intersections, Compute conditional probabilities and determine
independence of events and Apply Bayes' theorem to update probabilities given new information.
Every item follows the wording style and level of reasoning you meet in the real paper, and each
one is paired with a clear rationale so the correct choice is never a guess. Work through the set at
your own pace, mark the questions that slow you down, then come back to them until the
reasoning feels automatic. Learners who revise this way walk into the exam room recognising the
pattern behind the questions instead of meeting them for the first time. Keep going - steady, honest
practice is what turns a difficult paper into a comfortable pass.
Page 1
, Q1 APPLY THE AXIOMS OF PROBABILITY TO COMPUTE PROBABILITIES OF EVENTS,
INCLUDING COMPLEMENTS, UNIONS, AND INTERSECTIONS
A random variable X has the probability mass function P(X = k) = c * (1/3)^k for k =
0, 1, 2, ... . What is the value of the constant c?
A. 1/2
B. 2/3 CORRECT
C. 3/4
D. 1
RATIONALE: The sum of probabilities over all k must equal 1: sum_{k=0}^ c*(1/3)^k = c *
(1/(1-1/3)) = c * (3/2) = 1, so c = 2/3. Other options do not satisfy the normalization condition.
Q2 COMPUTE CONDITIONAL PROBABILITIES AND DETERMINE INDEPENDENCE OF EVENTS
Events A and B are such that P(A) = 0.4, P(B) = 0.5, and P(A B) = 0.7. Are A and B
independent?
A. Yes, because P(A B) = 0.2 = P(A)P(B). CORRECT
B. No, because P(A B) = 0.2 P(A)P(B).
C. Yes, because P(A B) = P(A) + P(B) - P(A)P(B).
D. No, because P(A B) = 0.1 P(A)P(B).
RATIONALE: P(A B) = P(A) + P(B) - P(A B) = 0.4 + 0.5 - 0.7 = 0.2. Since P(A)P(B) = 0.4*0.5 =
0.2, the events are independent. Option B incorrectly states 0.2 0.2, C misuses the union
formula, and D computes the intersection incorrectly.
Page 2
EXACT EXAM 2026/ QUESTIONS AND
VERIFIED ANSWERS GRADED A+
10 QUESTIONS
TABLE OF CONTENTS
# TOPIC
1 Apply the axioms of probability to compute probabilities of events, including complements, unions, and
intersections
2 Compute conditional probabilities and determine independence of events
3 Apply Bayes' theorem to update probabilities given new information
4 Calculate expected value and variance for discrete and continuous random variables
5 Identify and apply properties of binomial, Poisson, and normal distributions to solve problems
6 WGU C955
7 Module 7
8 Probability Exact Exam 2026
9 Questions and Verified Answers Graded A+
10 Foundations of Probability and Statistics
ABSTRACT
This study document brings together 10 carefully worded exam questions drawn from WGU C955 -
Module 7: Probability Exact Exam 2026/ Questions and Verified Answers Graded A+, with the
strongest emphasis placed on Apply the axioms of probability to compute probabilities of events,
including complements, unions, and intersections, Compute conditional probabilities and determine
independence of events and Apply Bayes' theorem to update probabilities given new information.
Every item follows the wording style and level of reasoning you meet in the real paper, and each
one is paired with a clear rationale so the correct choice is never a guess. Work through the set at
your own pace, mark the questions that slow you down, then come back to them until the
reasoning feels automatic. Learners who revise this way walk into the exam room recognising the
pattern behind the questions instead of meeting them for the first time. Keep going - steady, honest
practice is what turns a difficult paper into a comfortable pass.
Page 1
, Q1 APPLY THE AXIOMS OF PROBABILITY TO COMPUTE PROBABILITIES OF EVENTS,
INCLUDING COMPLEMENTS, UNIONS, AND INTERSECTIONS
A random variable X has the probability mass function P(X = k) = c * (1/3)^k for k =
0, 1, 2, ... . What is the value of the constant c?
A. 1/2
B. 2/3 CORRECT
C. 3/4
D. 1
RATIONALE: The sum of probabilities over all k must equal 1: sum_{k=0}^ c*(1/3)^k = c *
(1/(1-1/3)) = c * (3/2) = 1, so c = 2/3. Other options do not satisfy the normalization condition.
Q2 COMPUTE CONDITIONAL PROBABILITIES AND DETERMINE INDEPENDENCE OF EVENTS
Events A and B are such that P(A) = 0.4, P(B) = 0.5, and P(A B) = 0.7. Are A and B
independent?
A. Yes, because P(A B) = 0.2 = P(A)P(B). CORRECT
B. No, because P(A B) = 0.2 P(A)P(B).
C. Yes, because P(A B) = P(A) + P(B) - P(A)P(B).
D. No, because P(A B) = 0.1 P(A)P(B).
RATIONALE: P(A B) = P(A) + P(B) - P(A B) = 0.4 + 0.5 - 0.7 = 0.2. Since P(A)P(B) = 0.4*0.5 =
0.2, the events are independent. Option B incorrectly states 0.2 0.2, C misuses the union
formula, and D computes the intersection incorrectly.
Page 2
