WGU C810 ACTUAL EXAM 2026/2027:
100% Verified Questions & Correct Answers
Question 1:
A mid-size retailer’s data warehouse shows a 7 % drop in repeat-purchase rate over the last
two quarters. Which analytic deliverable best isolates whether the decline is driven by
fulfillment, pricing, or product-quality issues?
A. A real-time dashboard that visualizes daily sales by region.
B. A diagnostic root-cause model that segments cohorts by return-reason codes, Net
Promoter Score, and price-elasticity coefficients.
C. A predictive propensity-to-buy score for every new visitor.
D. An ARIMA forecast of total revenue for the next quarter.
Correct Answer: B
Rationale: C810 Competency 1—Descriptive & Diagnostic Analytics—requires decomposing a
metric change into explanatory variables; a segmented root-cause model directly addresses
the “why” behind the drop.
Question 2:
While building a random-forest model in Python you observe that training ROC-AUC = 0.97
while validation ROC-AUC = 0.73. Which action is most aligned with WGU’s best-practice
model-tuning framework?
A. Add more trees to the forest.
B. Increase max-depth and min_samples_leaf.
C. Implement k-fold cross-validation and a hyper-parameter grid that penalizes complexity.
D. Collect 10 % more rows and retrain on the full data set.
Correct Answer: C
Rationale: Competency 2—Predictive Analytics—identifies high variance (over-fit);
cross-validation with regularization mitigates it.
,Question 3:
A telecom firm wants to reduce churn. The marketing team needs to know which customers
will leave within 30 days and why. Which project methodology phase delivers the required
“why” explanation to non-technical stakeholders?
A. Data ingestion
B. Feature engineering
C. Model interpretability & SHAP summary reporting
D. API deployment
Correct Answer: C
Rationale: Competency 3—Explainable AI—mandates transparent models; SHAP reports
satisfy the “why” requirement.
Question 4:
You are creating a PostgreSQL data mart for ad-hoc queries. Surrogate keys are needed that
do not duplicate business keys. Which constraint enforces this rule at the database level?
A. PRIMARY KEY on the surrogate column.
B. UNIQUE on the business-key column.
C. CHECK (surrogate <> business_key).
D. FOREIGN KEY referencing the staging table.
Correct Answer: B
Rationale: Competency 4—Data Modeling—uses UNIQUE constraints to protect business-key
integrity while surrogate keys remain primary.
Question 5:
A logistics company streams IoT sensor events through Apache Kafka. Engineers want
exactly-once semantics when events are written to Snowflake. Which Kafka configuration
fulfills the requirement?
,A. enable.idempotence=true and transactional producer with commitTransaction().
B. set acks=0 for speed.
C. increase batch.size to 1 MB.
D. use ConsumerGroup with auto.commit.interval.ms=5000.
Correct Answer: A
Rationale: Competency 5—Streaming Data Pipelines—requires idempotent producers and
transactions for exactly-once delivery.
Question 6:
A business analyst asks why Snowflake query runtime doubled after adding a cluster key on
ORDER_DATE. Examination shows 90 % of table rows are from the last 30 days. Which
principle best explains the slowdown?
A. The cluster key created data skew.
B. Micro-partition pruning is less effective when clustering keys are highly correlated with
natural load order.
C. Cluster keys require virtual-warehouse resize.
D. Auto-scaling was disabled.
Correct Answer: B
Rationale: Competency 6—Cloud Data Warehousing—teaches that clustering already-ordered
data adds overhead without pruning benefit.
Question 7:
A data governance council mandates that any table containing PCI data must be tagged,
encrypted, and audited. Which Snowflake feature provides native tag-driven policy
enforcement?
A. Secure Views
B. Dynamic Data Masking
C. Classification & Tag-based Masking Policies (GA 2025)
, D. Search Optimization Service
Correct Answer: C
Rationale: Competency 7—Data Governance—uses classification tags to auto-apply
masking/encryption policies.
Question 8:
A financial dashboard shows Year-over-Year growth that disagrees with the audited 10-K.
Which documentation artifact should you consult first to locate the business-rule definition
for “net revenue”?
A. dbt.yml manifest file
B. Data Catalog glossary entry linked to the dashboard dataset
C. GitHub README in the analytics repo
D. Airflow DAG log
Correct Answer: B
Rationale: Competency 8—Data Catalog & Lineage—places certified definitions in the
governed glossary.
Question 9:
A dbt model “orders_fct” is configured with materialized=‘table’ and on_schema_change=‘fail’.
A source column is renamed from STATUS to ORDER_STATUS. What happens on the next dbt
run?
A. dbt automatically updates the model and appends the new column.
B. The run fails with a “column mismatch” error until the model SQL is updated.
C. dbt creates a view instead.
D. Full-refresh is triggered automatically.
Correct Answer: B
Rationale: Competency 9—dbt Deployment—enforces schema-change safeguards; “fail” stops
the pipeline for human review.
100% Verified Questions & Correct Answers
Question 1:
A mid-size retailer’s data warehouse shows a 7 % drop in repeat-purchase rate over the last
two quarters. Which analytic deliverable best isolates whether the decline is driven by
fulfillment, pricing, or product-quality issues?
A. A real-time dashboard that visualizes daily sales by region.
B. A diagnostic root-cause model that segments cohorts by return-reason codes, Net
Promoter Score, and price-elasticity coefficients.
C. A predictive propensity-to-buy score for every new visitor.
D. An ARIMA forecast of total revenue for the next quarter.
Correct Answer: B
Rationale: C810 Competency 1—Descriptive & Diagnostic Analytics—requires decomposing a
metric change into explanatory variables; a segmented root-cause model directly addresses
the “why” behind the drop.
Question 2:
While building a random-forest model in Python you observe that training ROC-AUC = 0.97
while validation ROC-AUC = 0.73. Which action is most aligned with WGU’s best-practice
model-tuning framework?
A. Add more trees to the forest.
B. Increase max-depth and min_samples_leaf.
C. Implement k-fold cross-validation and a hyper-parameter grid that penalizes complexity.
D. Collect 10 % more rows and retrain on the full data set.
Correct Answer: C
Rationale: Competency 2—Predictive Analytics—identifies high variance (over-fit);
cross-validation with regularization mitigates it.
,Question 3:
A telecom firm wants to reduce churn. The marketing team needs to know which customers
will leave within 30 days and why. Which project methodology phase delivers the required
“why” explanation to non-technical stakeholders?
A. Data ingestion
B. Feature engineering
C. Model interpretability & SHAP summary reporting
D. API deployment
Correct Answer: C
Rationale: Competency 3—Explainable AI—mandates transparent models; SHAP reports
satisfy the “why” requirement.
Question 4:
You are creating a PostgreSQL data mart for ad-hoc queries. Surrogate keys are needed that
do not duplicate business keys. Which constraint enforces this rule at the database level?
A. PRIMARY KEY on the surrogate column.
B. UNIQUE on the business-key column.
C. CHECK (surrogate <> business_key).
D. FOREIGN KEY referencing the staging table.
Correct Answer: B
Rationale: Competency 4—Data Modeling—uses UNIQUE constraints to protect business-key
integrity while surrogate keys remain primary.
Question 5:
A logistics company streams IoT sensor events through Apache Kafka. Engineers want
exactly-once semantics when events are written to Snowflake. Which Kafka configuration
fulfills the requirement?
,A. enable.idempotence=true and transactional producer with commitTransaction().
B. set acks=0 for speed.
C. increase batch.size to 1 MB.
D. use ConsumerGroup with auto.commit.interval.ms=5000.
Correct Answer: A
Rationale: Competency 5—Streaming Data Pipelines—requires idempotent producers and
transactions for exactly-once delivery.
Question 6:
A business analyst asks why Snowflake query runtime doubled after adding a cluster key on
ORDER_DATE. Examination shows 90 % of table rows are from the last 30 days. Which
principle best explains the slowdown?
A. The cluster key created data skew.
B. Micro-partition pruning is less effective when clustering keys are highly correlated with
natural load order.
C. Cluster keys require virtual-warehouse resize.
D. Auto-scaling was disabled.
Correct Answer: B
Rationale: Competency 6—Cloud Data Warehousing—teaches that clustering already-ordered
data adds overhead without pruning benefit.
Question 7:
A data governance council mandates that any table containing PCI data must be tagged,
encrypted, and audited. Which Snowflake feature provides native tag-driven policy
enforcement?
A. Secure Views
B. Dynamic Data Masking
C. Classification & Tag-based Masking Policies (GA 2025)
, D. Search Optimization Service
Correct Answer: C
Rationale: Competency 7—Data Governance—uses classification tags to auto-apply
masking/encryption policies.
Question 8:
A financial dashboard shows Year-over-Year growth that disagrees with the audited 10-K.
Which documentation artifact should you consult first to locate the business-rule definition
for “net revenue”?
A. dbt.yml manifest file
B. Data Catalog glossary entry linked to the dashboard dataset
C. GitHub README in the analytics repo
D. Airflow DAG log
Correct Answer: B
Rationale: Competency 8—Data Catalog & Lineage—places certified definitions in the
governed glossary.
Question 9:
A dbt model “orders_fct” is configured with materialized=‘table’ and on_schema_change=‘fail’.
A source column is renamed from STATUS to ORDER_STATUS. What happens on the next dbt
run?
A. dbt automatically updates the model and appends the new column.
B. The run fails with a “column mismatch” error until the model SQL is updated.
C. dbt creates a view instead.
D. Full-refresh is triggered automatically.
Correct Answer: B
Rationale: Competency 9—dbt Deployment—enforces schema-change safeguards; “fail” stops
the pipeline for human review.
