What distinguishes accuracy from precision in measurements?

The distinction between accuracy and precision is foundational in measurement and quality control contexts. Accuracy is defined as how close a measured value is to the actual or true value. For instance, if you're measuring the length of an object that is known to be 10 cm, an accurate measurement would be one that is very close to 10 cm.

On the other hand, precision refers to the degree to which repeated measurements under unchanged conditions show the same results. It focuses on the consistency of the measurements rather than their closeness to the true value. For example, if you consistently measure the length of the same 10 cm object and get values of 9.8 cm, 9.7 cm, and 9.9 cm, your measurements are precise but not accurate, because they cluster around a measurement that is not close to the true value of 10 cm.

Understanding this difference is crucial in settings such as manufacturing, where both qualities are important but in different contexts. High precision is valuable for repeatability, while accuracy ensures that the measurements lead to usable products.

In contrast to the other options, which either mischaracterize the definitions or lack fundamental distinctions between accuracy and precision, the correct choice accurately captures the essence of both terms.