CompTIA Data+ (DA0-001) Practice Test
Frequently asked questions
How many CompTIA Data+ (DA0-001) practice questions are here?+
A full bank of original CompTIA Data+ (DA0-001) practice questions across the official content areas, weighted like the real exam, with explanations. Free, no signup.
What is the CompTIA Data+ (DA0-001) exam like?+
A multiple-choice exam, 90 minutes, and you need 675/900% to pass. Practice by topic here, then take the full timed mock exam to gauge readiness.
Are these the real exam questions?+
No. Every question is 100% original, written from public primary sources with explanations. We never copy real exam questions or paid prep material.
Can I study in Chinese or Spanish?+
PrepPass practice is in English, 中文 and Español. The official exam is in English — switch the question language to English any time to rehearse the exact terminology you'll see on test day.
Sample practice questions
A few real questions from this free bank, with full explanations. Use the practice tool above for the whole set.
- 1. Data Concepts and Environments
A database is optimized for many small, fast insert and update operations from a business application, such as recording individual sales transactions. Which type of system is this?
- a.OLAP (online analytical processing)
- b.OLTP (online transaction processing)
- c.A flat CSV export
- d.A data visualization dashboard
Answer: b
Explanation: OLTP systems are optimized for numerous short, fast transactions such as inserts and updates from operational applications. OLAP systems, by contrast, are optimized for complex analytical queries over large historical datasets, which is a different workload.
- 2. Data Concepts and Environments
An organization stores vast amounts of raw data in its native format, both structured and unstructured, to be processed later as needed. Which environment is this?
- a.A data lake
- b.A normalized OLTP database
- c.A single spreadsheet
- d.A dimension table
Answer: a
Explanation: A data lake stores large volumes of raw data in its native format, deferring structure until the data is read and used. A normalized OLTP database enforces a strict schema up front, and a spreadsheet or single dimension table cannot hold the scale and variety described.
- 3. Data Mining
A dataset has a numeric column where about 3 percent of values are missing at random. The analyst replaces the missing values with the column's median. What is this technique called?
- a.Imputation
- b.Deduplication
- c.Parsing
- d.Encryption
Answer: a
Explanation: Imputation fills in missing values using a strategy such as the mean, median, or a model-based estimate so that records remain usable. Deduplication removes repeats, parsing splits or extracts fields, and encryption protects confidentiality, none of which replace missing values.
- 4. Data Mining
Before analysis, an analyst reviews a new dataset to summarize its structure, value ranges, null counts, and data types to assess its quality. What is this process called?
- a.Data visualization
- b.Data profiling
- c.Data encryption
- d.Data archiving
Answer: b
Explanation: Data profiling examines a dataset's structure, distributions, ranges, null counts, and types to understand its content and quality before deeper work. Visualization presents findings, encryption protects data, and archiving stores it long-term; none of those characterize the data upfront.
- 5. Data Analysis
A report summarizes what happened last quarter, showing total sales, average order value, and month-over-month change. Which type of analytics is this?
- a.Descriptive analytics
- b.Predictive analytics
- c.Prescriptive analytics
- d.Diagnostic analytics
Answer: a
Explanation: Descriptive analytics summarizes what has already happened using measures such as totals and averages. Diagnostic analytics explains why it happened, predictive forecasts what will happen, and prescriptive recommends what action to take.
- 6. Data Analysis
In hypothesis testing, an analyst obtains a p-value of 0.02 with a significance level (alpha) set at 0.05. What is the appropriate conclusion?
- a.Accept the null hypothesis as definitely true
- b.The result is inconclusive and no decision can be made
- c.Reject the null hypothesis because the p-value is below alpha
- d.Increase alpha to 0.50 to be safe
Answer: c
Explanation: When the p-value is less than the chosen significance level, the result is statistically significant and the null hypothesis is rejected in favor of the alternative. A p-value of 0.02 is below 0.05, so the analyst rejects the null; testing never proves the null definitively true.
- 7. Visualization
An analyst wants to show the trend of monthly website visits over the past three years. Which chart type is most appropriate?
- a.A pie chart
- b.A line chart
- c.A single-value scorecard
- d.A word cloud
Answer: b
Explanation: A line chart is ideal for showing how a value changes over a continuous time period, making trends and seasonality easy to read. A pie chart shows parts of a whole at one moment, a scorecard shows a single number, and a word cloud displays text frequency.
- 8. Visualization
An analyst wants to display the distribution of a single continuous variable by grouping values into ranges (bins) and showing how many fall in each. Which chart should be used?
- a.A histogram
- b.A pie chart
- c.A line chart of raw values
- d.A geographic map
Answer: a
Explanation: A histogram groups a continuous variable into bins and shows the frequency in each, revealing the shape of the distribution such as skew or modality. A pie chart shows composition, a line chart shows trends, and a map shows geography, none of which display a distribution this way.
- 9. Visualization
A regional sales manager wants to compare total sales across the 50 U.S. states at a glance, with color intensity showing higher versus lower values. Which visualization is most appropriate?
- a.A single line chart
- b.A choropleth (filled geographic map)
- c.A pie chart with 50 slices
- d.A one-row data table
Answer: b
Explanation: A choropleth map shades geographic regions by value, making spatial patterns across states immediately visible. A pie chart with 50 slices would be unreadable, a single line chart shows trends over time, and a raw table does not convey spatial patterns at a glance.
- 10. Data Governance, Quality, and Controls
An organization designates one authoritative source for customer records so that every system references the same trusted definition of a customer. Which practice is this?
- a.Master data management (MDM)
- b.Data visualization
- c.Encryption in transit
- d.A moving average
Answer: a
Explanation: Master data management establishes a single, authoritative source for core business entities such as customers or products, so all systems share a consistent, trusted definition. Visualization, encryption, and moving averages address other concerns entirely.