Performance Records for 18 Salespersons Are Selected to Investigate Whether

Multiple Choice

Performance records for 18 salespersons are selected to investigate whether compensation methods are a significant motivational factor. $\begin{array}{lc}\\ \text { Compensation Method } \quad\quad\quad\quad\quad\quad \quad \text { Sales }\\\begin{array}{|l|l|l|l|l|l|l|l|}\hline \text { Straight Salary } & 18 & 12 & 22 & 28 & 28 & & \\\hline \text { Straight Commission } & 27 & 34 & 34 & 27 & 20 & 16 & 24 \\\hline \text { Salary plus Commission } & 11 & 17 & 27 & 14 & 30 & 22 & \\\hline\end{array}\end{array}$
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 $\ge$ Group 3