WGU C207 DATA-DRIVEN DECISION MAKING OA PRACTICE
QUESTIONS, VERIFIED ANSWERS & RATIONALES 100%
CORRECT(Sampling Techniques)
Question 1 (Multiple Choice)
An auditor wants to select a random sample of 50 invoices from a population of 5,000 invoices.
Every 100th invoice on the master ledger is chosen after picking a random starting point
between 1 and 100. What sampling technique is being utilized?
● A. Simple random sampling
● B. Systematic sampling
● C. Stratified random sampling
● D. Cluster sampling
Correct Answer: B. Systematic sampling
Rationale: Systematic sampling involves selecting every k-th member from a population list
after a random starting point is chosen, which matches the procedure of selecting every 100th
invoice.
Question 2 (Multiple Choice)
A market researcher studying consumer preferences across a diverse city divides the
population into distinct neighborhoods (strata), ensuring that proportional random samples are
drawn from every single neighborhood. What is the primary benefit of this technique?
● A. It guarantees that minority or smaller subgroups are adequately represented in the
sample.
● B. It eliminates the need for any random selection.
● C. It reduces travel time and operational costs compared to simple random sampling.
● D. It ensures that the sample size is always smaller than 30 observations.
Correct Answer: A. It guarantees that minority or smaller subgroups are adequately
represented in the sample.
Rationale: Stratified random sampling divides the population into mutually exclusive subgroups
(strata) and samples from each, preventing small but important subgroups from being
accidentally omitted due to random chance.
Question 3 (Multiple Choice)
, A quality control manager at a manufacturing plant wants to inspect boxes of components.
Instead of selecting individual components from across the entire warehouse, the manager
randomly selects 10 entire boxes and inspects every single item inside those chosen boxes.
What sampling method is this?
● A. Stratified random sampling
● B. Cluster sampling
● C. Systematic sampling
● D. Convenience sampling
Correct Answer: B. Cluster sampling
Rationale: Cluster sampling involves dividing the population into groups (clusters, such as
boxes), randomly selecting entire clusters, and then examining every element within those
chosen clusters.
Question 4 (Multiple Choice)
An HR director surveys employees by standing outside the cafeteria during lunch and handing
questionnaires to the first 50 people who walk by. What type of sampling bias is most inherent in
this approach?
● A. Selection bias (convenience sampling)
● B. Sampling error reduction
● C. Stratified proportional weighting
● D. Systematic periodicity bias
Correct Answer: A. Selection bias (convenience sampling)
Rationale: Convenience sampling relies on readily available subjects rather than random
selection, introducing severe selection bias because not every member of the population has an
equal chance of being chosen.
Question 5 (Multiple Choice)
What is the primary difference between stratified sampling and cluster sampling?
● A. Stratified sampling takes random samples from every subgroup, whereas cluster
sampling randomly selects entire groups and tests all or a sample of elements within
those groups.
● B. Stratified sampling is non-probability based, while cluster sampling is strictly
probability based.
● C. Cluster sampling requires homogeneous groups, while stratified sampling requires
heterogeneous groups.
● D. Stratified sampling can only be used for qualitative data.
QUESTIONS, VERIFIED ANSWERS & RATIONALES 100%
CORRECT(Sampling Techniques)
Question 1 (Multiple Choice)
An auditor wants to select a random sample of 50 invoices from a population of 5,000 invoices.
Every 100th invoice on the master ledger is chosen after picking a random starting point
between 1 and 100. What sampling technique is being utilized?
● A. Simple random sampling
● B. Systematic sampling
● C. Stratified random sampling
● D. Cluster sampling
Correct Answer: B. Systematic sampling
Rationale: Systematic sampling involves selecting every k-th member from a population list
after a random starting point is chosen, which matches the procedure of selecting every 100th
invoice.
Question 2 (Multiple Choice)
A market researcher studying consumer preferences across a diverse city divides the
population into distinct neighborhoods (strata), ensuring that proportional random samples are
drawn from every single neighborhood. What is the primary benefit of this technique?
● A. It guarantees that minority or smaller subgroups are adequately represented in the
sample.
● B. It eliminates the need for any random selection.
● C. It reduces travel time and operational costs compared to simple random sampling.
● D. It ensures that the sample size is always smaller than 30 observations.
Correct Answer: A. It guarantees that minority or smaller subgroups are adequately
represented in the sample.
Rationale: Stratified random sampling divides the population into mutually exclusive subgroups
(strata) and samples from each, preventing small but important subgroups from being
accidentally omitted due to random chance.
Question 3 (Multiple Choice)
, A quality control manager at a manufacturing plant wants to inspect boxes of components.
Instead of selecting individual components from across the entire warehouse, the manager
randomly selects 10 entire boxes and inspects every single item inside those chosen boxes.
What sampling method is this?
● A. Stratified random sampling
● B. Cluster sampling
● C. Systematic sampling
● D. Convenience sampling
Correct Answer: B. Cluster sampling
Rationale: Cluster sampling involves dividing the population into groups (clusters, such as
boxes), randomly selecting entire clusters, and then examining every element within those
chosen clusters.
Question 4 (Multiple Choice)
An HR director surveys employees by standing outside the cafeteria during lunch and handing
questionnaires to the first 50 people who walk by. What type of sampling bias is most inherent in
this approach?
● A. Selection bias (convenience sampling)
● B. Sampling error reduction
● C. Stratified proportional weighting
● D. Systematic periodicity bias
Correct Answer: A. Selection bias (convenience sampling)
Rationale: Convenience sampling relies on readily available subjects rather than random
selection, introducing severe selection bias because not every member of the population has an
equal chance of being chosen.
Question 5 (Multiple Choice)
What is the primary difference between stratified sampling and cluster sampling?
● A. Stratified sampling takes random samples from every subgroup, whereas cluster
sampling randomly selects entire groups and tests all or a sample of elements within
those groups.
● B. Stratified sampling is non-probability based, while cluster sampling is strictly
probability based.
● C. Cluster sampling requires homogeneous groups, while stratified sampling requires
heterogeneous groups.
● D. Stratified sampling can only be used for qualitative data.
