Which of the Following Statements Are True?
A) When the Data

Which of the following statements are true?

A) When the data consists of pairs $\left( X _ { 1 } , Y _ { 1 } \right) , \ldots \ldots , \left( X _ { n } , Y _ { n } \right)$
And the differences $D _ { i } = X _ { i } - Y _ { i }$
(i = 1, . . . . . . ,n )
Are not assumed to be normally distributed, hypotheses tests about the expected differences $\mu _ { D }$
Can be tested by using the Wilcoxon signed-rank test on the $D _ { i } ^ { \prime } \text { s }$
Provided that the distribution of the differences is continuous and symmetric.
B) When the sample size n is larger than 20, it can be shown that the Wilcoxon signed-rank test statistic $S _ { + }$
Has approximately a normal distribution when the null hypothesis is true.
C) When the underlying distribution being sampled is normal, either the t test or the Wilcoxon signed-rank test can be used to test a hypothesis about the population mean $\mu .$
D) A number of different efficiency measures have been proposed by statisticians; one that many statisticians regard as credible is called asymptotic relative efficiency (ARE) .
E) All of the above statements are true.