Two-sample t test with equal variances
-----------------------------------------------------------------------------Variable |
Obs
Mean Std. Err. Std. Dev. [95% Conf. Interval]
---------+-------------------------------------------------------------------FEV |
654
2.63678 .0339047 .8670591 2.570204 2.703355
Sex |
654 .4862385 .0195591 .5001931 .4478322 .5246448
---------+-------------------------------------------------------------------combined | 1,308 1.561509 .0355999 1.287517
1.49167 1.631348
---------+-------------------------------------------------------------------diff |
2.150541 .0391419
2.073753 2.227329
-----------------------------------------------------------------------------diff = mean(FEV) - mean(Sex)
Ho: diff = 0
t = 54.9422
degrees of freedom =
Ha: diff < 0
Ha: diff != 0
Pr(T < t) = 1.0000
1306
Ha: diff > 0
Pr(|T| > |t|) = 0.0000
Pr(T > t) = 0.0000
D.
regress FEV Sex, beta
Source |
SS
df
MS
Number of obs =
-------------+---------------------------------- F(1, 652)
Model | 21.3239848
Residual | 469.595849
=
654
29.61
1 21.3239848 Prob > F
652 .720239032 R-squared
= 0.0000
= 0.0434
-------------+---------------------------------- Adj R-squared = 0.0420
Total | 490.919833
653 .751791475 Root MSE
= .84867
-----------------------------------------------------------------------------FEV |
Coef. Std. Err.
t P>|t|
Beta
-------------+---------------------------------------------------------------Sex | -.3612766 .0663963 -5.44 0.000
_cons | 2.812446 .0462987 60.75 0.000
-.208415
.