A Researcher Wants to Study the Effects of Physical Exercise

question 73

Multiple Choice

A researcher wants to study the effects of physical exercise on depression.She randomly selects a group of 24 individuals who are equally depressed.None of these individuals currently exercises.She then randomly assigns them in one of three groups: group 1 stays without exercising (sedentary group) , group 2 exercises once a week, and group 3 exercises two times a week.Individuals in groups 2 and 3 meet with a personal trainer so they carry out a very similar exercising program, both in kinds of exercises and in intensity.After two months, the researcher has all individuals take a depression-assessment test.The score of the test goes from 0 = totally miserable to 100 = complete satisfaction. The scores are shown in the following table:
$$\begin{array} { | c c c | } \hline \text { Group 1 } & \text { Group 2 } & \text { Group } 3 \\\hline 25 & 24 & 35 \\15 & 16 & 22 \\20 & 19 & 31 \\17 & 24 & 32 \\23 & 25 & 31 \\21 & 25 & 29 \\19 & 21 & 33 \\18 & 18 & 35 \\\hline\end{array}$$ The researcher uses a Kruskal-Wallis test and a significance level $\alpha$ = 0.05.The relevant number of degrees of freedom is ______.

• A)1
• B)2
• C)3
• D)23
• E)24

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Definitions:

Discrimination

Unfair or prejudicial treatment of different categories of people or things, especially on the grounds of race, age, or sex.

Chain Migration

The social process by which immigrants from a particular town follow others from that town to a new country or city, forming a new community.

Family Networking

The process of building and maintaining connections among family members for emotional support, resources, and guidance.

Ethnic Sharing

The action of sharing cultural, traditional, or ethnic backgrounds within a community, fostering a sense of identity and belonging.