A negative percent error indicates that the measured value of a quantity is less than the expected or true value. Percent error is a way of expressing the accuracy of a measurement compared to a known reference value. The formula for calculating percent error is:
Percent Error = ((Measured Value – True Value) / True Value) * 100
When the calculated result produces a negative value, it means:
- The measured value is smaller than the true value, suggesting an underestimation of the actual quantity.
- This discrepancy could occur due to various reasons such as instrument calibration errors, environmental factors, or procedural errors during measurement.
- Negative percent error is particularly relevant in fields like engineering, physics, and chemistry, where precision in measurements is critical.
For example, if the true value of a substance’s mass is 100 grams, but the measurement yields 90 grams, the percent error would be:
Percent Error = ((90 – 100) / 100) * 100 = -10%
This negative percentage indicates an underestimation, which can point to areas that need attention or adjustment in the measurement process.