1. Not finding help here? Sign up for a free 30min 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!

Physics lab work - calculating % errors

  1. Nov 24, 2011 #1
    I have a table of these 10 readings,

    149.6
    150.9
    149.7
    147.9
    147.7
    152.4
    149.8
    152.2
    153.2
    148.9


    They were taken on an optical bench where the smallest unit of measurement was 1mm. I'm trying to calculate the +- error but I'm not sure how to. I've came across 3 methods so far,

    1. Standard deviation

    2. [itex]\frac{max - min}{average}[/itex][itex]*100 *0.5[/itex]

    3. [itex]\frac{max - min}{no.values}[/itex]​

    Which should I use? Also, since the smallest unit of measurement was 1mm, should I round each of my readings to the nearest mm?
     
  2. jcsd
  3. Nov 24, 2011 #2

    gneill

    User Avatar

    Staff: Mentor

    You probably want the Standard Error in the Mean. When all the N samples have the same error [itex]\Delta x[/itex], the standard error would be [itex] \Delta x / \sqrt{N}[/itex].

    Take a look here at the section on the Standard Error in the Mean.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Physics lab work - calculating % errors
  1. Lab errors (Replies: 1)

  2. Physics 12 lab (work) (Replies: 7)

Loading...