[R] t-stat Curve

[Nordlund, Dan (DSHS)]

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-
> bounces at stat.math.ethz.ch] On Behalf Of Isaac Barjis
> Sent: Wednesday, September 27, 2006 8:08 AM
> To: R-help at stat.math.ethz.ch
> Subject: [R] t-stat Curve
> 
> Number of subjects = 25
> Mean of Sample = 77
> Standard Deviation (s) = 12
> sem = 2.4
> df = 24
> 
> The claim is that population mean is less than 80
> * > 80
> So our H0 (null hupotheis) is * > 80
> 
> 
> > qt(.95,24)
> [1] 1.710882
> > qt(0.05, 24)
> [1] -1.710882
> 
> tstat = -1.25 on t24 falls between 1.711 (.95,24) and *1.711 (.005,24)
> 
> 
> How Could I sketch t curve for the above data where my * would be at the
> center?
> 
> Best Regards
> Isaac
> 
> Dr. I. Barjis
> Assistant Professor
> Summer and Evening Coordinator
> Department of  Biological Sciences


Isaac,

I'm not sure that what you are asking for is reasonable (or possible).  It
is the sampling distribution of your t-statistic that is distributed as t
under the null hypothesis, not your observed data.  Could you clarify what
it is you wish to do?

Dan

Daniel J. Nordlund
Research and Data Analysis
Washington State Department of Social and Health Services
Olympia, WA  98504-5204