A Researcher Wants to Determine Whether the Means of Two $\quad$

question 29

Multiple Choice

A researcher wants to determine whether the means of two independent populations are the same.She has two independent random samples, one from each population, shown in the following table: $\quad$ $\quad$ $\quad$ $\quad$ Sample I $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ Sample II
$\begin{array}{llll|lllll}\hline 11.5 & 15.7 & 22.8 & 22.5 & 12.6 & 13.8 & 17.5 & 10.7 & 13.5 \\12.4 & 25.3 & 16.1 & 25.1 & 14.8 & 11.8 & 14.7 & 10.8 & 12.7\end{array}$

She uses the Mann-Whitney U test and a significance level of 0.05.Then $\mu$ _U is ______.

• A)4.5
• B)9
• C)31.5
• D)40
• E)63

---

Definitions:

Coevolution

Coevolution is the process by which two or more species reciprocally affect each other's evolution through natural selection.

Hawk Moth

A group of moths known for their rapid flight and ability to hover in place, often pollinating flowers as they feed on nectar.

Angraecum

A genus of orchids, primarily found in Madagascar, known for their elongated spur and nocturnal fragrance.

Polydactylism

A genetic variation resulting in more than the usual number of fingers or toes on the hands or feet, respectively.