Section 5.9.6 used some hypothetical data to illustrate the R function yuend with 20%

trimming. Use the function to compare the means. Verify that the estimated standard error of the difference between the sample means is smaller than the standard error of the difference between the 20% trimmed means. Despite this, the p-value is smaller when comparing trimmed means versus means. Why? Make general comments on this result. Next, compute the 20% trimmed mean of the difference scores. That is, set Di = Xi1 − Xi2 and compute the trimmed mean using the Di values. Compare this to the difference between the trimmed means of the marginal distributions, and make additional comments about comparing dependent groups.