Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Statistics Distributions?

  1. Feb 9, 2006 #1
    If you have a problem that involves some distribution, how do you know which one to use? The ones we covered so far are:
    Binomial
    Negative Binomial
    Hypergeometric
    Poisson Distribution
    Poisson Process
     
  2. jcsd
  3. Feb 10, 2006 #2

    Haelfix

    User Avatar
    Science Advisor

    You don't. You either take data and fit the distribution to one of those (and whichever one gives you the least error becomes the working model), or you guess the distribution from say first principles (say if you are a physicist and working on a physical problem).
     
  4. Feb 17, 2006 #3

    EnumaElish

    User Avatar
    Science Advisor
    Homework Helper

    Sometimes you may be able to trace distributions as "precedents" or "dependents" by uisng established analytical relations between distributions. E.g., if two variables are normally distributed, then their sum is also normal, and their quotient is Cauchy. The logarithm of a Normal variable has a Log Normal distribution. And, sometimes you can approximate (distributions approach one another under certain limit conditions, so it may be possible to use a simpler distribution in place of a more complex one).
     
  5. Feb 17, 2006 #4

    EnumaElish

    User Avatar
    Science Advisor
    Homework Helper

    And at some level, you do know. For example, you know whether it's a discrete or a continuous distribution. Also, we know that centain types of "experiments" are associated with certain distributions. Thus, a coin toss is associated with binomial; "consumer choice" is associated with multinomial; the number of balls in each of N boxes is associated with Chi-square; the number of customers arriving "between 9AM and 10AM" is associated wtih Poisson.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Statistics Distributions?
Loading...