Question

True or False

You test the hypothesis that 20% trimmed mean at time 1 are equal to the trimmed mean at time 2 using the R function yuend.This method is the same as testing the hypothesis that trimmed mean of the difference scores is to zero?

Answer 1

True

Let xi be values at time 1

Lwt yi be values at time 2

Let xbar be the trimmed mean at time 1

Let ybar be the trimeed mean at time 2

Let Trimmed mean of differences

dbar = (1/n) (xi - yi)

Testing trimmed mean x eqauls trimmed mean y

Is equivalent to test

Trimmed mean x - trimmed mean y = 0

= (1/n)xi - (1/n)yi = 0

= (1/n) (xi - yi) = 0

= dbar = 0

Hence it is equivalent to test trimmed mean of differences