On Jan 15, 2004, at 2:33 AM, Kristen wrote:
Does anyone know a way to specify the difference in a ttest? The
default
result is:
Ho = diff = 0
I hope to be able to do:
Ho = diff = #
where # is the standard deviation or other pre-determined value.
. reg price foreign
Source | SS df MS Number of obs =
74
-------------+------------------------------ F( 1, 72) =
0.17
Model | 1507382.66 1 1507382.66 Prob > F =
0.6802
Residual | 633558013 72 8799416.85 R-squared =
0.0024
-------------+------------------------------ Adj R-squared =
-0.0115
Total | 635065396 73 8699525.97 Root MSE =
2966.4
------------------------------------------------------------------------
------
price | Coef. Std. Err. t P>|t| [95% Conf.
Interval]
-------------
+----------------------------------------------------------------
foreign | 312.2587 754.4488 0.41 0.680 -1191.708
1816.225
_cons | 6072.423 411.363 14.76 0.000 5252.386
6892.46
------------------------------------------------------------------------
------
. test foreign=200
( 1) foreign = 200
F( 1, 72) = 0.02
Prob > F = 0.8821
This does the same thing as ttest price, by(foreign), but allows you to
specify your own value for the difference. The null for the ttest is
that foreign=0. I imagine it could also be done with anova and test,
but don't see how the "second syntax" in help testanova is supposed to
work.
Kit
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