2026 UPDATED QUESTIONS DOWNLOAD
WGU C955 Applied Probability and Statistics - ULTIMATE MASTER BANK (350 Q&A) –
Full Study Guide: Regression, Probability & Z-Scores (2025-2026)
This 350-question master bank is the most comprehensive resource available for WGU C955.
It covers all critical domains: Descriptive Statistics, Probability, Correlation and
Regression, and Sampling/Study Design. Each question includes a detailed italicized
rationale explaining the statistical logic. Perfect for passing the Objective Assessment (OA) on
your first attempt!
1. A researcher gathers data on the number of pets owned by households in a specific
neighborhood. What type of data is this?
A) Continuous
B) Discrete
C) Categorical
D) Qualitative
Correct Answer: B
Rationale: Discrete data consists of counted values that cannot be divided (you can have 2 or
3 pets, but not 2.5 pets).
2. Which measure of center is most affected by outliers (extremely high or low values)?
A) Median
B) Mode
C) Mean
D) Interquartile Range
Correct Answer: C
Rationale: The mean uses the actual value of every data point; therefore, a single very large
number will pull the average significantly higher.
3. In a normal distribution, approximately what percentage of data falls within two
standard deviations of the mean?
A) 68%
B) 95%
C) 99.7%
D) 50%
Correct Answer: B
Rationale: Following the Empirical Rule (68-95-99.7 rule), 95% of data in a bell curve falls
within ±2 standard deviations.
4. A bag contains 4 red marbles, 3 blue marbles, and 3 green marbles. If one marble is
picked at random, what is the probability it is NOT blue?
A) 0.3
, 2026 UPDATED QUESTIONS DOWNLOAD
B) 0.7
C) 0.4
D) 0.6
Correct Answer: B
Rationale: There are 10 total marbles. 3 are blue, so 7 are NOT blue.
.
5. Which correlation coefficient (r) indicates the strongest linear relationship?
A) 0.85
B) -0.92
C) 0.05
D) -0.50
Correct Answer: B
Rationale: The strength of a correlation is determined by how close it is to 1 or -1. -0.92 is
closer to an absolute value of 1 than 0.85.
6. A study finds that as the amount of time spent exercising increases, resting heart rate
decreases. This is an example of:
A) Positive Correlation
B) No Correlation
C) Negative Correlation
D) Causation
Correct Answer: C
Rationale: Negative correlation occurs when two variables move in opposite directions (one
up, one down).
7. What is the "Mode" of the following data set: {2, 4, 4, 7, 8, 9, 10, 10, 10}?
A) 4
B) 7
C) 10
D) 6.4
Correct Answer: C
Rationale: The mode is the value that appears most frequently in a data set.
8. A researcher observes a group of people and records their dietary habits without
giving them any specific instructions or treatments. This is a(n):
A) Experimental Study
B) Blind Study
C) Observational Study
D) Controlled Trial
, 2026 UPDATED QUESTIONS DOWNLOAD
Correct Answer: C
Rationale: In an observational study, the researcher does not manipulate variables or apply a
"treatment."
9. In a box-and-whisker plot, the "box" represents which part of the data?
A) The entire range
B) The middle 50% (Interquartile Range)
C) The outliers
D) The mean
Correct Answer: B
Rationale: The box represents the data between the first quartile (Q1) and third quartile (Q3).
10. If the probability of an event happening is 2/5, what is the probability of its
complement?
A) 1/5
B) 2/5
C) 3/5
D) 5/2
Correct Answer: C
Rationale: The sum of an event and its complement must equal 1.
.
11. Which of the following is an example of a "Continuous" variable?
A) Number of children in a family
B) Pages in a book
C) The exact weight of a bag of flour
D) Number of cars in a parking lot
Correct Answer: C
Rationale: Weight can be measured to infinite decimal places, making it continuous rather than
counted.
12. A data set is "Right Skewed." Where is the "tail" of the distribution?
A) On the left
B) In the center
C) On the right
D) There is no tail
Correct Answer: C
Rationale: In a skewed distribution, the name of the skew tells you the direction of the long tail.
, 2026 UPDATED QUESTIONS DOWNLOAD
13. What is the probability of rolling a 4 on a fair six-sided die AND then flipping
"Heads" on a coin?
A) 1/6
B) 1/2
C) 1/8
D) 1/12
Correct Answer: D
Rationale: For independent events, multiply the probabilities:
.
14. A survey asks 100 people for their favorite color. What type of data is being
collected?
A) Quantitative
B) Discrete
C) Qualitative (Categorical)
D) Continuous
Correct Answer: C
Rationale: Colors are categories/labels, not numerical measurements.
15. If the mean of a data set is 50 and the standard deviation is 5, what is the Z-score for
a value of 60?
A) 1
B) 2
C) 5
D) 10
Correct Answer: B
Rationale:
WGU C955 Applied Probability and Statistics - ULTIMATE MASTER BANK (350 Q&A) –
Full Study Guide: Regression, Probability & Z-Scores (2025-2026)
This 350-question master bank is the most comprehensive resource available for WGU C955.
It covers all critical domains: Descriptive Statistics, Probability, Correlation and
Regression, and Sampling/Study Design. Each question includes a detailed italicized
rationale explaining the statistical logic. Perfect for passing the Objective Assessment (OA) on
your first attempt!
1. A researcher gathers data on the number of pets owned by households in a specific
neighborhood. What type of data is this?
A) Continuous
B) Discrete
C) Categorical
D) Qualitative
Correct Answer: B
Rationale: Discrete data consists of counted values that cannot be divided (you can have 2 or
3 pets, but not 2.5 pets).
2. Which measure of center is most affected by outliers (extremely high or low values)?
A) Median
B) Mode
C) Mean
D) Interquartile Range
Correct Answer: C
Rationale: The mean uses the actual value of every data point; therefore, a single very large
number will pull the average significantly higher.
3. In a normal distribution, approximately what percentage of data falls within two
standard deviations of the mean?
A) 68%
B) 95%
C) 99.7%
D) 50%
Correct Answer: B
Rationale: Following the Empirical Rule (68-95-99.7 rule), 95% of data in a bell curve falls
within ±2 standard deviations.
4. A bag contains 4 red marbles, 3 blue marbles, and 3 green marbles. If one marble is
picked at random, what is the probability it is NOT blue?
A) 0.3
, 2026 UPDATED QUESTIONS DOWNLOAD
B) 0.7
C) 0.4
D) 0.6
Correct Answer: B
Rationale: There are 10 total marbles. 3 are blue, so 7 are NOT blue.
.
5. Which correlation coefficient (r) indicates the strongest linear relationship?
A) 0.85
B) -0.92
C) 0.05
D) -0.50
Correct Answer: B
Rationale: The strength of a correlation is determined by how close it is to 1 or -1. -0.92 is
closer to an absolute value of 1 than 0.85.
6. A study finds that as the amount of time spent exercising increases, resting heart rate
decreases. This is an example of:
A) Positive Correlation
B) No Correlation
C) Negative Correlation
D) Causation
Correct Answer: C
Rationale: Negative correlation occurs when two variables move in opposite directions (one
up, one down).
7. What is the "Mode" of the following data set: {2, 4, 4, 7, 8, 9, 10, 10, 10}?
A) 4
B) 7
C) 10
D) 6.4
Correct Answer: C
Rationale: The mode is the value that appears most frequently in a data set.
8. A researcher observes a group of people and records their dietary habits without
giving them any specific instructions or treatments. This is a(n):
A) Experimental Study
B) Blind Study
C) Observational Study
D) Controlled Trial
, 2026 UPDATED QUESTIONS DOWNLOAD
Correct Answer: C
Rationale: In an observational study, the researcher does not manipulate variables or apply a
"treatment."
9. In a box-and-whisker plot, the "box" represents which part of the data?
A) The entire range
B) The middle 50% (Interquartile Range)
C) The outliers
D) The mean
Correct Answer: B
Rationale: The box represents the data between the first quartile (Q1) and third quartile (Q3).
10. If the probability of an event happening is 2/5, what is the probability of its
complement?
A) 1/5
B) 2/5
C) 3/5
D) 5/2
Correct Answer: C
Rationale: The sum of an event and its complement must equal 1.
.
11. Which of the following is an example of a "Continuous" variable?
A) Number of children in a family
B) Pages in a book
C) The exact weight of a bag of flour
D) Number of cars in a parking lot
Correct Answer: C
Rationale: Weight can be measured to infinite decimal places, making it continuous rather than
counted.
12. A data set is "Right Skewed." Where is the "tail" of the distribution?
A) On the left
B) In the center
C) On the right
D) There is no tail
Correct Answer: C
Rationale: In a skewed distribution, the name of the skew tells you the direction of the long tail.
, 2026 UPDATED QUESTIONS DOWNLOAD
13. What is the probability of rolling a 4 on a fair six-sided die AND then flipping
"Heads" on a coin?
A) 1/6
B) 1/2
C) 1/8
D) 1/12
Correct Answer: D
Rationale: For independent events, multiply the probabilities:
.
14. A survey asks 100 people for their favorite color. What type of data is being
collected?
A) Quantitative
B) Discrete
C) Qualitative (Categorical)
D) Continuous
Correct Answer: C
Rationale: Colors are categories/labels, not numerical measurements.
15. If the mean of a data set is 50 and the standard deviation is 5, what is the Z-score for
a value of 60?
A) 1
B) 2
C) 5
D) 10
Correct Answer: B
Rationale:
