The percentage error is 100% times the relative error.
See also
Absolute Error, Error Propagation, Percent, Relative Error
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References
Abramowitz, M. and Stegun, I. A. (Eds.). Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, 9th printing. New York: Dover, p. 14, 1972.
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Cite this as:
Weisstein, Eric W. "Percentage Error." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/PercentageError.html