Mathematica 7.0 - Wrong Documentation on StudentTCI

*To*: mathgroup at smc.vnet.net*Subject*: [mg105094] Mathematica 7.0 - Wrong Documentation on StudentTCI*From*: Lawrence Teo <lawrenceteo at yahoo.com>*Date*: Fri, 20 Nov 2009 06:41:47 -0500 (EST)

Hi all, Summary: StudentTCI function's second parameter expects standard error, rather than standard deviation as stated in the document. The document has an error. I just want to report an error in the documentation of StudentTCI function in Mathematica 7.0. The document for StudentTCI function reads StudentTCI[Mu,Sigma, df] gives a confidence interval {min, max} for the population mean based on the sample mean Mu and sample standard deviation Sigma. (refer to HypothesisTesting/ref/StudentTCI) The truth is StudentTCI function expects Standard Error in the second parameter, rather than a Standard Deviation. I was driven crazy by the funny behavior of StudentTCI function for hours. To make things worse, I didn't suspect it at all and were busy looking for other mistakes in a rather complex code. I found it in HypothesisTesting/tutorial/HypothesisTesting. The documentation is slightly different and clearly points out the second parameter is a standard error. It was a great relief to me after knowing this document mistake. Hope it helps the rest of the Mathematica users.

**Follow-Ups**:**Re: Mathematica 7.0 - Wrong Documentation on StudentTCI***From:*Darren Glosemeyer <darreng@wolfram.com>