Wize University Statics Textbook (Master) > Introduction

Percent Error

Percent error helps us to compare the error size with the actual value of a quantity.

It can be calculated using the following equation:

%Error=∣Theoretical Value−Experimental ValueTheoretical Value∣×100%\displaystyle \%\text{Error}=\left|\frac{\text{Theoretical  Value}-\text{Experimental Value}}{\text{Theoretical Value}}\right|\times100\%%Error=​Theoretical ValueTheoretical Value−Experimental Value​​×100%

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Example: Percent Error 

An experiment finds that the acceleration due to gravity is 10.2m/s2. What is the percentage error in this experiment? Use g=9.8m/s2 as the accepted value for gravity.

Solution:
%Error=∣Theoretical Value−Experimental ValueTheoretical Value∣×100=∣9.8−10.29.8∣×100%=∣−0.49.8∣×100%=4.08%\begin{aligned}
\%\text{Error} &=\left|\frac{\text{Theoretical  Value}-\text{Experimental Value}}{\text{Theoretical Value}}\right|\times100\\[11pt]
&= \left|\frac{9.8-10.2}{9.8}\right|\times100\%\\[9pt]
&=\left|\frac{-0.4}{9.8}\right|\times100\%\\[9pt]
&=4.08\%
\end{aligned}%Error​=​Theoretical ValueTheoretical Value−Experimental Value​​×100=​9.89.8−10.2​​×100%=​9.8−0.4​​×100%=4.08%​

Find the percent error if the molar mass of carbon is 12.01 but the experiment product a value of 12.1.

0.75%

7.5%

75 %

I don't know