Contributor
Posts: 28

# proc ttest

what is Diff(1-2) in proc ttest procedure?

PROC Star
Posts: 1,285

## Re: proc ttest

Posted in reply to VISHNU239

They are simple statistics for the two populations being compared.

For an example and explanation, see PROC TTEST: Comparing Group Means

They are listed in Figure 92.5 and explained above

Contributor
Posts: 28

## Re: proc ttest

how the values are calculated for the diff(1-2) for pooled and satterthwhaite in the attachment listed below.

Contributor
Posts: 28

## Re: proc ttest

Posted in reply to VISHNU239

https://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_ttest_sect0...

in the above link when the observations are only 30 in the output table N=44 .why?

Respected Advisor
Posts: 3,066

## Re: proc ttest

Posted in reply to VISHNU239

VISHNU239 wrote:

https://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_ttest_sect0...

in the above link when the observations are only 30 in the output table N=44 .why?

This is clearly explained in the text at that link.

--
Paige Miller
Contributor
Posts: 28

## Re: proc ttest

Posted in reply to PaigeMiller
that is what i didnt understood. what has it to do with the count included in the freq?
Super User
Posts: 23,776

## Re: proc ttest

Posted in reply to VISHNU239

@VISHNU239 wrote:
that is what i didnt understood. what has it to do with the count included in the freq?

Count tells SAS how to weight the observations. If you have three identical responses for example, rather than have three entries, you can have the count=3 instead.

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