Percentage error

1. Sep 25, 2005

Kandy

I forgot how to do percentage error, actually I kind of forgot what it is. I do remember multiplying somthg by 100% but i cant remember what i divide b4 that.

2. Sep 25, 2005

Atomos

In terms of percent error with regards to an accepted value:
Suppose you measured the atomic molar mass of lithium to be 8 g/mol. The accepted value is 6.94. You take the difference, which is 1.06g/mol, and the percent error is therefore +15.27% ie. 1.06/6.94 * 100%

3. Sep 26, 2005

HallsofIvy

Staff Emeritus
Theoretically, you divide the error by the true value. In practice, you have an error because you don't know the true value! In that case you divide the (estimated error) by the measured value.