Welch's two-sample t-test is used with small sample sizes when the variances of the populations are not equal. Welch's two-sample t-test leverages [[Welch's approximation]]. Use [[R]] to conduct a Welch's t-test. ```R x <- rnorm(10) # generate data for x y <- rnorm(14) # generate data for y t.test(x,y,conf.level=0.90) ```