1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How to calculate the average with uncertainties?

  1. Feb 28, 2017 #1
    1. The problem statement, all variables and given/known data
    How to calculate the average given the uncertainties in each measurement 8.70 +/- 0.28, 9.680 +/- 0.046, 9.700 +/- 0.055, 9.720 +/- 0.067?

    2. Relevant equations

    3. The attempt at a solution
    I know I add the values and divide by 4. I also know I add the absolute uncertainties but idk if I divide them by 4. Please help I've gotten 9.45 +/- 0.448 meters
  2. jcsd
  3. Mar 1, 2017 #2


    User Avatar
    Science Advisor
    Homework Helper
    2017 Award

    Hello Tyler, :welcome:

    In the case off different accuracies, you have to weight the measurements when averaging. The appropriate weight of a measurement is ##1\over \sigma^2##.
    Here, ##\sigma## is the (estimated) inaccuracy
    Last edited: Mar 1, 2017
  4. Mar 1, 2017 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    It's "weight the measurements".
    Well, it's not so much the accuracy as the inaccuracy.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted