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Homework Help: Percentage uncertainty and percentage difference

  1. Mar 17, 2012 #1
    my teacher said that percentage uncertainty is a measure of precision and percentage difference a measure of accuracy.
    i thought it's the other way round??
    say if i have 20%
    and 80%
    what do these values tell me in terms of precision and accuracy?
  2. jcsd
  3. Mar 17, 2012 #2


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    Staff Emeritus
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    Homework Helper

    I think your teacher has it correct. For uncertainty and precision, you need not even know what the "correct" value is. For percent difference and also accuracy, you are comparing your measurement to the "correct" value that has already been determined by other means.
    I need more context to answer that question. What are you saying the 20% and the 80% numbers represent? 80% is not a very good value for either precision or accuracy.
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