Performance records for 18 salespersons are selected to investigate whether compensation methods are a significant motivational factor.
A Kruskal-Wallis test is to be performed with $\alpha$= 0.01.The null hypothesis is ___.
A)Group 1 = Group 2 = Group 3
B)Group 1 $\neq$ Group 2 $\neq$ Group 3
C)Group 1 $\ge$ Group 2 $\ge$Group 3
D)Group 1 $\le$ Group 2 $\le$Group 3
E)Group 1 $\le$ Group 2 ≥ Group 3

Question

Performance records for 18 salespersons are selected to investigate whether compensation methods are a significant motivational factor.  
A Kruskal-Wallis test is to be performed with $\alpha$= 0.01.The null hypothesis is ___.
A)Group 1 = Group 2 = Group 3 
B)Group 1 $\neq$ Group 2 $\neq$ Group 3 
C)Group 1 $\ge$ Group 2 $\ge$Group 3 
D)Group 1 $\le$ Group 2 $\le$Group 3 
E)Group 1 $\le$ Group 2 ≥ Group 3

Quizplus · Accepted Answer

The null hypothesis for a Kruskal-Wallis test is that the population medians of all groups are equal. Therefore, in this case, the null hypothesis is that the compensation methods have no significant effect on sales performance, and all groups (salespersons) have the same median performance. This corresponds to choice A, "Group 1 = Group 2 = Group 3."

Performance Records for 18 Salespersons Are Selected to Investigate Whether α\alphaα

Performance Records for 18 Salespersons Are Selected to Investigate Whether $\alpha$