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Need help with Wilcoxon rank-sum test

  1. Mar 30, 2012 #1
    Hi guys,

    Can anybody help with regards to this question??

    Suppose we want to compare the length of hospital stay for patients with same diagnosis at two different hospitals hospital

    First hospital: 5,8,10,13,21,26,29,32,33,44,60
    Second hospital: 10,27,35,44,60,68,73,76,86,87,96,125,238

    Question1: why might t-test not be very useful in this case? Book said, data is very skewed, but how I can find that myself.

    Qestion 2:
    Carry out non-parametric procedure for testing the length of stay are comparable in the two hospitals

    The question is answered in the back of the book and I did calculate it by software, but I would like to know how to do it manually, I tried to apply Wilcoxon sum test formula but failed to get the same numbers.

    The answers: use Wilcoxon rank-sum test(large-sample test), R1=83.5, T=3.10 , p=.002

    Thanks for your help!
  2. jcsd
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