Suppose that 6 economists who work for the federal government and 7 university economists were asked to predict the percentage change in the Canada's GDP over the three year period from January 2013 to January 2016. The Wilcoxon rank-sum test was used to determine if the two groups differ in their predictions. The value of the test statistic was calculated to be 29.5. At α = 0.05, we can conclude that
A) the null hypothesis should be rejected.
B) the alternative hypothesis should not be rejected.
C) there is a difference in predictions provided by the two groups of economists.
D) since TL= 28

Question

Suppose that 6 economists who work for the federal government and 7 university economists were asked to predict the percentage change in the Canada's GDP over the three year period from January 2013 to January 2016. The Wilcoxon rank-sum test was used to determine if the two groups differ in their predictions. The value of the test statistic was calculated to be 29.5. At α = 0.05, we can conclude that
A) the null hypothesis should be rejected.
B) the alternative hypothesis should not be rejected.
C) there is a difference in predictions provided by the two groups of economists.
D) since TL= 28 < 29.5 < TU = 56, we can conclude that two groups of economists have different predictions.
E) the null hypothesis should not be rejected; there is no significant difference in predictions provided by the two groups of economists.

Quizplus · Accepted Answer

The Wilcoxon rank-sum test is a non-parametric test used to compare two independent samples to determine whether there is a significant difference between them. The decision to reject or not reject the null hypothesis is based on comparing the test statistic to a critical value or using a p-value approach, depending on the test's specifics and the available tables or software. The statement "since TL= 28 < 29.5 < TU = 56, we can conclude that two groups of economists have different predictions" is incorrect in the context of this test's interpretation. The correct interpretation of the given test statistic, 29.5, falling between the lower and upper critical values (TL and TU), is that there is not enough evidence to reject the null hypothesis, implying there is no significant difference in predictions between the two groups of economists at the α = 0.05 significance level.

Suppose That 6 Economists Who Work for the Federal Government