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Question about expected frequencies within ranges

  1. Mar 7, 2012 #1
    Say I have ranges:
    (-infinity to 16) where the observed frequency is 35
    (16 to 18) where the obs freq is 100
    (18 to 20) where the obs.. freq. is 360
    (20 to 22) where the obs. freq. is 326
    (22 to 24) where the obs. freq. is 150
    (24 to infinity) where the obs freq is 29

    The mean is 20 and standard deviation is 2

    How would i find the expected value of each range?
  2. jcsd
  3. Mar 7, 2012 #2
    anyone have an idea on how to do this?
  4. Mar 7, 2012 #3
    i meant to ask how to find the expected frequency not value? sorry
  5. Mar 7, 2012 #4


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    Science Advisor
    Gold Member

    I saw your post on a previous forum - there is no good answer.
  6. Mar 7, 2012 #5
    yes its possible. I have done it before but forgot the method I used. I was hoping someone knew how to do it.
  7. Mar 7, 2012 #6


    User Avatar
    Staff Emeritus
    Science Advisor

    If all you know is that there are 100 observations between 16 and 18, but do not know where they they lie, you can't calculate an expected value.

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