# Independent group T-Test

## Equal variances

Null hypothesis : Y and X have the same mean.

Test : Use a two sided test with unequal variances to test equivalence.

R code : t.test(mean(Y), mean(X), paired = FALSE, var.equal = TRUE)

#### Unequal variances

Null hypothesis : Y and X have the same mean.

Test : Use a two sided test with unequal variances to test equivalence.

Mean difference interval :

R code : t.test(mean(Y), mean(X), paired = FALSE, var.equal = FALSE)

**When in doubt, assume independent group and unequal variances!**