A student in the laboratory measures thickness of a wire using screw gauge. The readings are $1.22$ mm, $1.23$ mm, $1.19$ mm and $1.20$ mm. The percentage error is $\frac{x}{121}\%$. The value of $x$ is \_\_\_\_.
A student in the laboratory measures thickness of a wire using screw gauge. The readings are $1.22$ mm, $1.23$ mm, $1.19$ mm and $1.20$ mm. The percentage error is $\frac{x}{121}\%$. The value of $x$ is \_\_\_\_.