What formula represents the calculation of relative percent error (RPE)?

The correct formula for calculating relative percent error (RPE) is expressed as RPE = 100 x (measured value - target value) / target value. This formula effectively provides a way to measure how close a measured value is to a target or expected value, expressed as a percentage of the target value.

In this context, the 'measured value' refers to the actual value obtained from a test or experiment, while the 'target value' is the known or expected value that serves as a reference point. The difference between these two values (measured value minus target value) indicates the absolute error, and when this error is divided by the target value and multiplied by 100, it expresses that error as a percentage of the target, thus contextualizing the error in relation to the target value.

Using relative percent error is particularly beneficial in fields such as radon measurement because it allows for a standardized comparison of errors across different measurements, providing insight into measurement accuracy relative to expected results. In a practical application, this can guide professionals in determining whether the radon levels measured are acceptable or require further action.