. ttest begsalry==8
One-sample t test
------------------------------------------------------------------------------
Variable | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval]
---------+--------------------------------------------------------------------
begsalry | 105 8.842857 .1264684 1.295915 8.592066 9.093649
------------------------------------------------------------------------------
mean = mean(begsalry) t = 6.6646
Ho: mean = 8 degrees of freedom = 104
Ha: mean < 8 Ha: mean != 8 Ha: mean > 8
Pr(T < t) = 1.0000 Pr(|T| > |t|) = 0.0000 Pr(T > t) = 0.0000
也就是说可以否定虚无假设,接受研究假设了吧 可是为什么要选择mean>8的假设呢?
追答mean > 8 是因为 begsalry 的均值为8.842857, 此外 Ha: mean > 8 下面的 Pr(T > t) = 0.0000 表示 这个假设出错的可能为0.0000