本人刚学stata,大家多多指教.这是用stata的做的一个输出结果,

本人刚学stata,大家多多指教.这是用stata的做的一个输出结果,
.regress y x1 x2 x3
Source | SS df MS Number of obs = 15
-------------+------------------------------ F( 3,11) = 2.39
Model | .314572294 3 .104857431 Prob > F = 0.1239
Residual | .481761032 11 .043796457 R-squared = 0.3950
-------------+------------------------------ Adj R-squared = 0.2300
Total | .796333326 14 .056880952 Root MSE = .20928
------------------------------------------------------------------------------
y | Coef.Std.Err.t P>|t| [95% Conf.Interval]
-------------+----------------------------------------------------------------
x1 | 9.57e-06 .0000596 0.16 0.875 -.0001217 .0001408
x2 | .0000724 .0001414 0.51 0.619 -.0002389 .0003837
x3 | .0006278 .0002514 2.50 0.030 .0000745 .0011811
_cons | 1.132732 .4274603 2.65 0.023 .1918985 2.073566
------------------------------------------------------------------------------
.
其中的_cons,coef.这个用的是什么统计方法,方程成不成立,回归效果如何.