st: ask for help about ttesti

From	rghuang <0034058@fudan.edu.cn>
To	statalist <statalist@hsphsun2.harvard.edu>
Subject	st: ask for help about ttesti
Date	Sat, 13 Dec 2003 23:04:18 +0800

if i want to use

ttesti #obs1 #mean1 #sd1 #obs2 #mean2 #sd2 or ttesti #obs #mean #sd

but i just don't know what sd is,just know variance.how should i do?

do i have to use display to compute sd first?or still have some other ways?

thank you.