You measure a piece of rope and find its length to be 12 m. How do you find the percent error of this measurement?

1 Answer
Aug 27, 2017

You can only do so by knowing its actual length, which you have not provided.


And if we somehow already know the true length to be #"12.2 m"# for some reason or another, then the percent error would be:

#barul|stackrel(" ")(" "%"error" = (|"measured" - "true value"|)/("true value") xx 100%" ")|#

And with your measured #"12 m"#, then it would be:

#= (|12 - 12.2|)/(12.2) xx 100%#

#= 1.64%#

Given the measurement was made to two significant figures, the difference was #"0.2 m"#, but the percent difference was #color(blue)(1.6%)#.