2 sample t test stata
stata ttest by groupstata compare means across groups
test command stata
paired t-test stata
t-test stata interpretation
t-test stata multiple variables
f test stata

test performs Wald tests of simple and composite linear hypotheses about the parameters of the most recently fit model. test supports svy estimators (see Often researchers want to test for differences between levels of a factor (categorical variable) or factors after running an anova or regress command. Test that the mean of v1 is equal between two groups defined by catvar ttest v1, by(catvar) sets of values to be compared are in different variables. In the first form, ttest tests that varname has a mean of #. In the second form, ttest tests that varname has the same mean within the two groups defined by sdtest performs tests on the equality of standard deviations (variances). Robust equality of variances test for v1 comparing the groups defined by Specifically, you use an independent t-test to determine whether the mean difference between two groups is statistically significantly different to zero. ForUnpaired z test that the mean of v1 is equal between two groups defined by catvar ztest v1, by(catvar). As above, and adjust for clustering with clusters