A Researcher Wants to Determine Whether the Means of Two

Multiple Choice

A researcher wants to determine whether the means of two independent populations are the same.She has two independent random samples,one from each population,shown in the following table: She uses the Mann-Whitney U test and a significance level of 0.05.This is a ______ test,and the critical ______.

A) one-tailed; value is 1.96
B) two-tailed; values are ±1.96
C) one-tailed; value is 1.645
D) two-tailed; values are ±1.645
E) one-tailed; value is −1.96