comptia data+ practice test Practice Exam 2025: Latest Questions

A data analyst is asked to combine customer records from a CRM system and a support ticketing system. The two systems use different customer identifiers, and some customers appear multiple times due to spelling variations. Which technique BEST addresses this before analysis?

A dataset contains a column for "purchase_amount" where some values are extremely high due to data entry errors. The analyst wants a quick way to reduce the impact of these extreme values on summary statistics without removing rows. Which approach is MOST appropriate?

A business user wants to compare quarterly revenue across three regions in a dashboard. Which visualization is BEST suited for quickly comparing values across categories?

An analyst needs to ensure that a calculated metric in a report is interpreted the same way across teams. Which artifact MOST directly supports this goal?

A retailer wants to group customers into segments based on similar purchasing behavior without predefined labels. Which data mining technique should the analyst use?

A dataset has 120,000 rows with an outcome column "churn" where only 3% of customers churned. The analyst trains a model and gets 97% accuracy, but leadership says it is not useful. Which evaluation metric would BEST help assess performance on the minority class?

A dashboard shows month-over-month sales trends, but users report that the trend line changes dramatically depending on the selected date range. The analyst suspects the smoothing method is causing confusion. Which change is MOST likely to improve interpretability while keeping the trend view?

A data analyst is asked to choose a storage approach for a curated analytics dataset that will be queried heavily for reporting and requires consistent definitions for dimensions like customer and product. Which approach BEST fits this requirement?

A healthcare organization shares de-identified patient data with an external research partner. After release, the partner demonstrates that individuals can be re-identified by combining quasi-identifiers (e.g., ZIP code, age band, and visit date) with public datasets. Which control MOST directly reduces this risk while keeping the dataset useful for analysis?

A team built a churn prediction model and reports strong performance. During review, an analyst notices the feature set includes a field "cancellation_processed_date" that is only populated after a customer cancels. What is the MOST likely issue, and what is the best corrective action?

A data analyst needs to combine two tables: Customers (CustomerID, Name) and Orders (OrderID, CustomerID, Total). The analyst must keep all Customers even if they have no Orders. Which join type should be used?

A dashboard uses a pie chart to show market share across 18 competitors. Users complain they cannot accurately compare slices. Which change is the BEST improvement?

A dataset includes a column named "Country" with values like "US", "USA", and "United States". Which data quality issue is MOST directly represented?

A retailer wants to identify products that are frequently purchased together in the same transaction to improve cross-selling. Which data mining technique is MOST appropriate?

A data analyst builds a predictive model and gets very high accuracy on the training data but much lower accuracy on new, unseen data. Which problem is MOST likely occurring?

A BI report shows monthly revenue. After a data pipeline change, revenue appears inflated. Investigation reveals a one-to-many join between Orders and OrderItems is being aggregated at the order level without deduplication. What is the MOST likely root cause?

A dataset has an "Age" field intended to be numeric, but some records contain values like "N/A" and "unknown". The analyst needs to run statistical summaries without losing the ability to review these problematic records later. What is the BEST approach?

An analyst is asked to visualize the distribution of call wait times and highlight potential outliers across multiple call centers. Which visualization is BEST suited for this purpose?

A healthcare analytics team must provide a de-identified dataset to a vendor for model development. The vendor must not be able to re-identify individuals, but the team still needs to link repeated visits from the same patient across time. Which approach BEST meets the requirement?

A company wants near-real-time metrics from IoT sensors for anomaly detection and alerting, while also retaining raw events for long-term analysis. Which architecture BEST supports both needs?

A data analyst is asked to publish a dashboard that shows customer spend by zip code. Some zip codes have fewer than five customers, and leadership still wants geographic insights. What is the BEST approach to reduce re-identification risk while keeping the dashboard useful?

A dataset contains the field values for State as: "CA", "California", "Calif.", "Cali", and "ca". Downstream reports show multiple entries for what should be the same state. Which data quality issue is being demonstrated?

A team runs a daily ETL job that appends data to an analytics table. After a schema change in the source system, the job completes without errors, but several numeric columns in the target are now NULL. Which control would BEST detect this issue early?

A business user complains that a report showing "average order value" is much higher than expected. The dataset includes a few extremely large corporate orders among many small consumer orders. Which measure would BEST represent the typical order value for the consumer segment?

A team wants to publish a set of curated KPIs (e.g., revenue, churn) used across multiple departments. Different analysts currently compute the KPIs differently in separate tools, causing conflicting results. Which solution BEST improves consistency and governance while enabling self-service analytics?