[spam] t.test confidence interval - R-help

Sun, Apr 10, 2005 8:31 PM #

Hi,

I'm using R for some undergraduate lectures, reaching the t tests.
No matter what conf.level one specifies in the syntax, the output always shows 
the 95 percent confidence interval.
Is it possible to alter the function somehow, to report the CL percent 
confidence interval?

TIA,
Adrian

-- 
Adrian Dusa
Romanian Social Data Archive
Bd. Schitu Magureanu nr.1
Tel./Fax: +40 21 3126618 \
              +40 21 3120210 / int.101

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Peter Dalgaard

Fri, Apr 15, 2005 4:53 AM #

Adrian Dusa <dusa.adrian at gmail.com> writes:

That's just not true in my version of R.

Welch Two Sample t-test

data:  extra by group
t = -1.8608, df = 17.776, p-value = 0.0794
alternative hypothesis: true difference in means is not equal to 0
80 percent confidence interval:
 -2.7101645 -0.4498355
sample estimates:
mean in group 1 mean in group 2
           0.75            2.33

O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
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Adrian Dusa

Fri, Apr 15, 2005 10:18 AM #

On 15 Apr 2005 13:53:32 +0200, Peter Dalgaard <p.dalgaard at biostat.ku.dk> wrote:

You're right of course. I just typed "cl" instead of "conf" or
"conf.level" and it took the predefined 0.95. Sorry to bothering you.