WGU BEC1 — Statistics
Expanded Final Exam Study Guide • 2026/2027
Independent practice bank • calculations • rationales • formulas • interpretation • high-yield traps
The referenced Stuvia listing is a 54-page Q&A; resource for STATISTICS BEC1. This guide is independently authored from the public listing and WGU's
published course descriptions; it does not reproduce the paid resource or claim to contain leaked/actual assessment questions.
Coverage
• Descriptive statistics and graphical displays
• Sampling, bias and research design
• Probability and conditional probability
• Expected value
• Normal distribution and z-scores
• Correlation, regression, residuals and R²
• Confidence intervals and hypothesis testing
• Statistical versus practical significance
WGU BEC1 Statistics • Independent Study Guide • 2026/2027 Page 1
, 1. Data, Sampling & Research Design
Q1. A population is:
A. The subset measured
B. The entire group of interest
C. A numerical summary
D. A graph
Answer: B
Rationale: A population is the complete group about which the study seeks information.
Q2. A sample is:
A. The entire population
B. A subset selected from the population
C. Always a parameter
D. A graph
Answer: B
Rationale: A sample is a subset used to learn about a larger population.
Q3. A numerical measure describing a population is a:
A. Statistic
B. Parameter
C. Residual
D. Frequency
Answer: B
Rationale: A parameter describes a population; a statistic describes a sample.
Q4. Which sampling method uses a random mechanism to select members from a population?
A. Simple random sampling
B. Convenience sampling
C. Voluntary response
D. Judgment sampling
Answer: A
Rationale: Simple random sampling is based on random selection.
Q5. Surveying only people leaving one gym is most vulnerable to:
A. Convenience/selection bias
B. Random assignment
C. Blinding
D. Placebo effect
Answer: A
Rationale: People at one gym may differ systematically from the broader target population.
Q6. An observational study is one in which researchers:
A. Assign treatments randomly
B. Observe variables without imposing a treatment
C. Always use a census
D. Eliminate confounding
Answer: B
Rationale: Researchers measure existing conditions rather than assigning treatments.
Q7. Random assignment primarily helps:
A. Generalize to every population
B. Balance confounding variables across treatment groups
C. Increase sample size
D. Remove all measurement error
Answer: B
Rationale: Random assignment helps make treatment groups comparable on average.
WGU BEC1 Statistics • Independent Study Guide • 2026/2027 Page 2
, Q8. Random sampling primarily helps with:
A. Generalizing sample results to a population
B. Proving causation
C. Increasing effect size
D. Eliminating all bias
Answer: A
Rationale: Random sampling supports representative inference; it does not establish causality.
Q9. A confounding variable is one whose effect:
A. Is unrelated to the study
B. Is mixed with effects of variables being studied
C. Is always the response
D. Is always random
Answer: B
Rationale: Confounding makes it difficult to isolate effects.
Q10. Which design gives the strongest basis for a causal claim?
A. Randomized controlled experiment
B. Convenience survey
C. Retrospective observational study
D. Voluntary-response poll
Answer: A
Rationale: Manipulation plus random assignment provides strong evidence for causation.
Q11. A question worded to push respondents toward one answer creates:
A. Leading-question bias
B. Randomization
C. Stratification
D. Blocking
Answer: A
Rationale: Wording can systematically influence responses.
Q12. A variable that is measured as a category such as 'yes/no' is:
A. Categorical
B. Continuous
C. Numerical interval only
D. A parameter
Answer: A
Rationale: Categorical variables classify observations into groups.
2. Descriptive Statistics & Graphs
Q13. The mean of 4, 6, 8, and 12 is:
A. 6
B. 7
C. 7.5
D. 8
Answer: C
Rationale: (4+6+8+12)/4 = 7.5.
Q14. The median of 3, 5, 9, 10, 20 is:
A. 5
B. 9
C. 10
D. 20
Answer: B
Rationale: The middle ordered observation is 9.
WGU BEC1 Statistics • Independent Study Guide • 2026/2027 Page 3
Expanded Final Exam Study Guide • 2026/2027
Independent practice bank • calculations • rationales • formulas • interpretation • high-yield traps
The referenced Stuvia listing is a 54-page Q&A; resource for STATISTICS BEC1. This guide is independently authored from the public listing and WGU's
published course descriptions; it does not reproduce the paid resource or claim to contain leaked/actual assessment questions.
Coverage
• Descriptive statistics and graphical displays
• Sampling, bias and research design
• Probability and conditional probability
• Expected value
• Normal distribution and z-scores
• Correlation, regression, residuals and R²
• Confidence intervals and hypothesis testing
• Statistical versus practical significance
WGU BEC1 Statistics • Independent Study Guide • 2026/2027 Page 1
, 1. Data, Sampling & Research Design
Q1. A population is:
A. The subset measured
B. The entire group of interest
C. A numerical summary
D. A graph
Answer: B
Rationale: A population is the complete group about which the study seeks information.
Q2. A sample is:
A. The entire population
B. A subset selected from the population
C. Always a parameter
D. A graph
Answer: B
Rationale: A sample is a subset used to learn about a larger population.
Q3. A numerical measure describing a population is a:
A. Statistic
B. Parameter
C. Residual
D. Frequency
Answer: B
Rationale: A parameter describes a population; a statistic describes a sample.
Q4. Which sampling method uses a random mechanism to select members from a population?
A. Simple random sampling
B. Convenience sampling
C. Voluntary response
D. Judgment sampling
Answer: A
Rationale: Simple random sampling is based on random selection.
Q5. Surveying only people leaving one gym is most vulnerable to:
A. Convenience/selection bias
B. Random assignment
C. Blinding
D. Placebo effect
Answer: A
Rationale: People at one gym may differ systematically from the broader target population.
Q6. An observational study is one in which researchers:
A. Assign treatments randomly
B. Observe variables without imposing a treatment
C. Always use a census
D. Eliminate confounding
Answer: B
Rationale: Researchers measure existing conditions rather than assigning treatments.
Q7. Random assignment primarily helps:
A. Generalize to every population
B. Balance confounding variables across treatment groups
C. Increase sample size
D. Remove all measurement error
Answer: B
Rationale: Random assignment helps make treatment groups comparable on average.
WGU BEC1 Statistics • Independent Study Guide • 2026/2027 Page 2
, Q8. Random sampling primarily helps with:
A. Generalizing sample results to a population
B. Proving causation
C. Increasing effect size
D. Eliminating all bias
Answer: A
Rationale: Random sampling supports representative inference; it does not establish causality.
Q9. A confounding variable is one whose effect:
A. Is unrelated to the study
B. Is mixed with effects of variables being studied
C. Is always the response
D. Is always random
Answer: B
Rationale: Confounding makes it difficult to isolate effects.
Q10. Which design gives the strongest basis for a causal claim?
A. Randomized controlled experiment
B. Convenience survey
C. Retrospective observational study
D. Voluntary-response poll
Answer: A
Rationale: Manipulation plus random assignment provides strong evidence for causation.
Q11. A question worded to push respondents toward one answer creates:
A. Leading-question bias
B. Randomization
C. Stratification
D. Blocking
Answer: A
Rationale: Wording can systematically influence responses.
Q12. A variable that is measured as a category such as 'yes/no' is:
A. Categorical
B. Continuous
C. Numerical interval only
D. A parameter
Answer: A
Rationale: Categorical variables classify observations into groups.
2. Descriptive Statistics & Graphs
Q13. The mean of 4, 6, 8, and 12 is:
A. 6
B. 7
C. 7.5
D. 8
Answer: C
Rationale: (4+6+8+12)/4 = 7.5.
Q14. The median of 3, 5, 9, 10, 20 is:
A. 5
B. 9
C. 10
D. 20
Answer: B
Rationale: The middle ordered observation is 9.
WGU BEC1 Statistics • Independent Study Guide • 2026/2027 Page 3
