Which statistic is used to confirm accuracy?

• A. Mean
• B. SD and CV
• C. Range
• D. Median

Answer: (A)

Accuracy is about how close measurements are to the true value. When you repeat a measurement, the average (mean) of those values serves as the best estimate of the true value if the measurements are unbiased, so it is used to assess accuracy. A value close to the known standard indicates good accuracy, while a consistent bias reveals systematic error.

The other metrics describe precision, not accuracy. Standard deviation and the coefficient of variation quantify how spread out the measurements are, i.e., how reproducible they are. The range shows how far apart the extreme values are, giving spread but not closeness to the true value. The median is another central tendency measure, but it does not directly indicate how close measurements are to the true value in the way the mean does.