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Homework Help: Percentage error

  1. Sep 25, 2005 #1

    Kandy

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    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.
     
    Kandy, Sep 25, 2005
  2. jcsd
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  3. Sep 25, 2005 #2

    Atomos

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    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%
     
    Atomos, Sep 25, 2005
  4. Sep 26, 2005 #3

    HallsofIvy

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    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.
     
    HallsofIvy, Sep 26, 2005
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