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Hypothesis test for normality on the TI-84?

  1. Jan 9, 2012 #1
    I'm trying to run a hypothesis test to see if a data set follows a normal distribution. I don't want to look at a plot. Is there any way? I tried to build a program that uses the built-in normal distribution functions to calculate how far the points on a normality plot would fall from forming a straight line, but I get errors.

    Any ideas?
     
  2. jcsd
  3. Jan 9, 2012 #2

    jedishrfu

    Staff: Mentor

  4. Jan 9, 2012 #3
    Here is the code I am using. Instead of filling List 3 with the normal CDF values, it fills List 3 with a bunch of 0's.

    Code (Text):

    SortA(L1)
    N->dim(L1)
    For(I,1,N)
    (I/N)->L2(I)
    normalcdf(0,L1(I),mean(L1),stdDev(L1))->L3(I)
    End
     
  5. Jan 9, 2012 #4

    jedishrfu

    Staff: Mentor

    Shouldnt the normalcdf be outside loop?
     
  6. Jan 10, 2012 #5
    I don't think normalcdf will take lists for X values. But I will try that as soon as I can.
    As it happens, I created another macro that just calculates the cumulative frequency. That one does work. I know how to have my normalcdf macro execute my cumulative frequency macro. For the reference, I just press "PRGM," in the EXEC highlight that macro and press "ENTER," that big button on the bottom-right.
     
  7. Jan 13, 2012 #6
    Update: I changed the code.

    Now it's this:

    Code (Text):
    prgmCUMFREQ
    (L1-mean(L1))/stdDev(L1)->L3
    For (I,1,dim(L1))
    normalcdf(-1e99,L3(I),0,1)->L4(I)
    End
     
    Now it won't give me those zeroes.

    But now I have another problem. When I fill in data from my statistics textbook, I get a different p-value than what my statistics textbook reads. I am reasonably certain I did not mistype any data.

    UPDATE: Here's the code for my cumulative frequency macro:

    Code (Text):
    PROGRAM:CUMFREQ
    SortA(L1)
    For(I,1,dim(L1))
    I/dim(L1)->L2(I)
    End
     
     
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