CompTIA Data+ (DA0-002)Data Governance, Quality and ControlsHard
A data quality team audits 2,500 customer records against a trusted reference dataset to verify that field values correctly represent real-world facts. The audit finds that 2,275 records match the reference data exactly. Which value represents the accuracy rate of this dataset?
- A94%
- B91%
- C85%
- D88%
Show answer & explanationAnswer & explanation
Correct answer: B. 91%
Accuracy rate = (matching records / total records) x 100 = (2,275 / 2,500) x 100 = 0.91 x 100 = 91%. This measures how well the dataset reflects real-world truth as validated against the trusted reference.
Why the other options are wrong
- A. 94% overstates the accuracy rate; the math does not support this value.
- C. 85% does not match the calculated ratio of 2,275/2,500.
- D. 88% is not the result of the correct division.
Accuracy Rate Calculation
A metric expressing the percentage of records that correctly match a trusted reference source, calculated as (matching records ÷ total records) × 100.
- Accuracy differs from validity (accuracy checks truth, not just format)
- Formula: matching records ÷ total records × 100
- Requires a trusted reference source for comparison
Memory trick: Divide the matches by the total, then dress it up in a percent hat.