Researchers examined a new treatment for advanced ovarian cancer in a mouse model. They created a nanoparticle-based delivery system for a suicide-gene therapy to be delivered directly to the tumor cells. The mice were randomly assigned to have their tumors injected with either the gene -- nanoparticle combination, the gene alone, or some buffer solution (placebo). The following table shows the tumor fold-increases after two weeks in a total of 29 mice. A fold-increase of 1 represents no change; a fold-increase of 2 represents a doubling in volume of the tumor.
$$\begin{array} { | c | c | c | }
\hline \text { Buffer } & \text { Gene } & \text { Gene+Nano } \
\hline 3.3 & 2.7 & 1.1 \
3.8 & 3.0 & 1.1 \
4.1 & 3.3 & 1.2 \
5.4 & 3.4 & 1.4 \
5.4 & 3.9 & 1.8 \
6.8 & 4.3 & 1.8 \
7.0 & 5.3 & 2.1 \
7.8 & 5.6 & 2.1 \
8.1 & 5.6 & 3.5 \
9.1 & & 4.1 \
\hline
\end{array}$$ Software gives H = 16.7 for these data. What is the P-value of the Kruskal-Wallis test?

Question

Researchers examined a new treatment for advanced ovarian cancer in a mouse model. They created a nanoparticle-based delivery system for a suicide-gene therapy to be delivered directly to the tumor cells. The mice were randomly assigned to have their tumors injected with either the gene -- nanoparticle combination, the gene alone, or some buffer solution (placebo). The following table shows the tumor fold-increases after two weeks in a total of 29 mice. A fold-increase of 1 represents no change; a fold-increase of 2 represents a doubling in volume of the tumor.
$$\begin{array} { | c | c | c | } 
\hline \text { Buffer } & \text { Gene } & \text { Gene+Nano } \
\hline 3.3 & 2.7 & 1.1 \
3.8 & 3.0 & 1.1 \
4.1 & 3.3 & 1.2 \
5.4 & 3.4 & 1.4 \
5.4 & 3.9 & 1.8 \
6.8 & 4.3 & 1.8 \
7.0 & 5.3 & 2.1 \
7.8 & 5.6 & 2.1 \
8.1 & 5.6 & 3.5 \
9.1 & & 4.1 \
\hline
\end{array}$$ Software gives H = 16.7 for these data. What is the P-value of the Kruskal-Wallis test?

Quizplus · Accepted Answer

The Kruskal-Wallis test H value of 16.7 for these data suggests a significant difference between the groups. Given the context of the question and the typical interpretation of H values in relation to P-values, an H value of 16.7 would correspond to a P-value less than 0.01, indicating a highly significant difference between the treatment groups.

Researchers Examined a New Treatment for Advanced Ovarian Cancer in a Mouse