The Kruskal-Wallis test is to be used to determine whether there is a significant difference in the satisfaction rating (alpha = 0.05)between three brands of boxed cake mix.Shoppers were asked to rate their satisfaction on various attributes and an aggregate satisfaction score ranging from 1-50 was computed.The following data were obtained: $$\begin{array} { c c c c c c }
\text { Cake Mix A } & 19 & 21 & 25 & 22 & 33 \
\text { Cake Mix B } & 30 & 24 & 28 & 31 & 35 \
\text { Cake Mix C } & 39 & 32 & 41 & 42 & 27
\end{array}$$ For this test, how many degrees of freedom should be used?
A)3
B)2
C)4
D)8
E)1

Question

The Kruskal-Wallis test is to be used to determine whether there is a significant difference in the satisfaction rating (alpha = 0.05)between three brands of boxed cake mix.Shoppers were asked to rate their satisfaction on various attributes and an aggregate satisfaction score ranging from 1-50 was computed.The following data were obtained: $$\begin{array} { c c c c c c } 
\text { Cake Mix A } & 19 & 21 & 25 & 22 & 33 \
\text { Cake Mix B } & 30 & 24 & 28 & 31 & 35 \
\text { Cake Mix C } & 39 & 32 & 41 & 42 & 27
\end{array}$$ For this test, how many degrees of freedom should be used?
A)3
B)2
C)4
D)8
E)1

Quizplus · Accepted Answer

The Kruskal-Wallis test uses the ranks of the data rather than the actual values, and calculates a test statistic that follows a chi-squared distribution with degrees of freedom equal to the number of groups minus one. In this case, there are three groups, so the degrees of freedom should be (3-1) = 2. Therefore, the best choice is B.

The Kruskal-Wallis Test Is to Be Used to Determine Whether