Originally Posted by

**dadon** hey!

I was wondering if anyone knew anything about 95% confidence limits from a 't' distribution?

..and if it is possible an example.

thanks.

dadon

The Wikipedia article on the t-distribution is very good and can be found here

A example is shown in the following code block showing a computer session

computing a 95% confidence interval for the mean:

Code:

>
>N=10;
>x=normal(N,1)
-0.309911
-2.01066
-0.568246
-1.0841
-0.277172
-1.4568
0.658046
1.53204
-2.47296
-0.937381
>m=mean(x')
-0.692714
>
>s=sqrt(sum((x'-m)^2)/(N-1))
1.19313
>
>..95% region for T-distribution with 9 DF is +/-2.26 (looked up
>..in a table of the T-distribution)
>
>..so the 95% region for the sample mean is m+/-2.26*s/sqrt(N)
>
>[m-2.26*s/sqrt(N),m+2.26*s/sqrt(10)]
-1.54541 0.159986
>
>

RonL