Dear Statalisters,
after performing the following ttest, I would like to know about a possible
way to obtain with Stata 9.2/SE the one-way 95 CI for Ha: diff < 0.
Thanks a lot for your kindness and for your time.
Kind Regards and enjoy your W-E,
Carlo
ttest qaly, by(treat) unequal
Two-sample t test with unequal variances
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Group Obs Mean Std. Err. Std. Dev. [95% Conf. Interval]
0 250 1.1472 .0158906 .2512527 1.115903
1.178497
1 250 1.1872 .0157876 .249624 1.156106 1.218294
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Combined 500 -.0399999 .0224 -.0840101 .0040102
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diff = mean(0) - mean(1) t = -1.7857
Ho: diff = 0 Satterthwaite's degrees of freedom =497.979
Ha: diff < 0 Ha: diff != 0 Ha: diff > 0
Pr(T < t) = 0.0374 Pr(|T| > |t|) = 0.0748 Pr(T > t) =0.9626
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