如图:a2和b2都符合正态(sktest和swilk检验都>0.05),方差不齐,代码为 ttest a2==b2, unpaired unequal welch
. ttest a2==b2, unpaired unequal welch
Two-sample t test with unequal variances
------------------------------------------------------------------------------
Variable | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval]
---------+--------------------------------------------------------------------
a2 | 16 .0567185 .0034406 .0137622 .0493851 .0640519
b2 | 16 .0537502 .0078743 .0314973 .0369665 .0705339
---------+--------------------------------------------------------------------
combined | 32 .0552344 .0042351 .0239574 .0465968 .0638719
---------+--------------------------------------------------------------------
diff | .0029683 .0085932 -.0148887 .0208253
------------------------------------------------------------------------------
diff = mean(a2) - mean(b2) t = 0.3454
Ho: diff = 0 Welch's degrees of freedom = 21.2627
Ha: diff < 0 Ha: diff != 0 Ha: diff > 0
Pr(T < t) = 0.6334 Pr(|T| > |t|) = 0.7332 Pr(T > t) = 0.3666
.
数据如下:a2
.0520833
.0606061
.0578035
.0714286
.0694444
.0352113
.0361011
.0621118
.0574713
.0609756
.0529101
.0826446
.0694444
.0425532
.0361011
.0606061
b2
.0191939
.0182815
.025641
.0337838
.0444444
.0625
.030303
.0628931
.031746
.018018
.0806452
.1020408
.0869565
.0512821
.1176471
.0746269
谢谢各位!!