R contains data, stored in the R variable sleep, which show the effect of two soporific drugs, namely the increase in hours of sleep compared to control. Create a boxplot for both groups using the command boxplot(sleep[[1]] sleep[[2]]) and speculate about whether comparing 20% trimmed means will give a result similar to Welch’s test.

Use the R command z=selby.v3(sleep,2,1)$x to separate the data into two groups and use the function yuen to check your answer.