Dear Calc team,

the following wording is ambiguous and it may be wrong altogether:

> function description:
> calculates the probability of a *sample* mean greater than the mean of
> the given *sample*.
[EMPHASIS ADDED]

So, does it compute the probabilities based on 2 samples?
I doubt it.

I may go back to basics. Lets say we have a population (P) with
a population mean Mu(P), and a sample X, with a sample mean mu(X).

The statistical hypothesis are:
H0: Mu(P) == mu(X)
Ha: Mu(P) either '<' or '>' mu(X) [the one tailed version]

Depending on the tail used, it will be '<' or '>'.
The 2-tailed version is Mu(P) '!=' mu(X).

I haven't followed the discussion recently, so I am unable
to tell exactly what is computed.

But I very much suspect that it compares mu(X) against
a population mean Mu(P).

Also, the phrase dose not specify what statistics is used.
It might be obvious that the z-statistic is used, but I would
rather specify it explicitly. There are a lot of different statistics
out there.

Sincerely,

Leonard Mada


-------- Original-Nachricht --------
> Datum: 25 Aug 2009 07:20:41 -0000
> Von: [email protected]
> An: [email protected]
> Betreff: [Issue 90759] ZTEST not same as Excel

> To comment on the following update, log in, then open the issue:
> http://www.openoffice.org/issues/show_bug.cgi?id=90759
> 
> 
> 
> 
> 
> ------- Additional comments from [email protected] Tue Aug 25 07:20:40
> +0000 2009 -------
> Our proposal for the function wizard:-
> 
> function description:
> calculates the probability of a sample mean greater than the mean of
> the given sample.
> 
> first parameter
> The given sample, drawn from a normally distributed population
> 
> second parameter
> The known mean of the population
> 
> third parameter
> The known standard deviation of the population. If omitted, the standard
> deviation of the given sample is used. 
> 
> 
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