Date:         Fri, 4 Sep 2009 09:20:00 +0000
Reply-To:     Ruben van den Berg <ruben_van_den_berg@hotmail.com>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Ruben van den Berg <ruben_van_den_berg@hotmail.com>
Subject:      Confidence interval for extremely skewed metric variable
In-Reply-To:  <EBCD4B2FF2A24DE68054ABBE64DFC463@NOTEBOOK>
Content-Type: multipart/alternative;


Dear all,

 

I want to estimate a confidence interval for the mean of a metric variable that's extremely skewed to the right. As I (hopefully!) understood, the central limit theorem will make sure that the sampling distribution of the mean will follow a Gaussian distribution (assuming enough observations). However, the skewed distribution causes the standard deviation to be very large compared to the mean value, rendering a very wide confidence interval that's not too informative.

 

Is there any way (e.g. by a transformation or something) to obtain a smaller interval?

 

TIA!

 

Ruben van den Berg

 

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