How do I calculate percentage error?

My manual says % error = mL error / vol. grad cyl * 100%



I filled my beaker to 19 the difference was 2.6 how do i find the error?How do I calculate percentage error?
Explain yourself - filled what beaker to 19 whats?

2.6 was the difference between 19 and what?



I think you are confused here!



http://drtchemistry.wordpress.com/How do I calculate percentage error?
Percent Error = ( (Calculated value - Real value) / Real Value ) * 100.



If the value you found was 19, and the actual value was 21.6:

Percent Error = ( (19 - 21.6) / 21.6 ) * 100.

Percent Error = ( (19 - 21.6) / 21.6 ) * 100.

Percent Error = ( -2.6 / 21.6 ) * 100.

Percent Error = ( -0.1203703704 ) * 100.

Percent Error = -12.03703704%



After significant figures, the answer is -12%.