A Researcher Wants to Study the Effects of Physical Exercise

question 8

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 critical chi-square value is ______.

• A)9.35
• B)7.82
• C)7.38
• D)6.82
• E)5.99

---

Definitions:

AVC

Average Variable Cost, which is the cost a company incurs to produce each additional unit of product, excluding fixed costs.

ATC

Average Total Cost, which is the total cost of production divided by the quantity of output produced.

Total Revenue

The total income generated by a firm or economy from its sale of goods and services, calculated before any expenses are subtracted.

Profit Maximizing

The process by which a firm determines the price and output level that returns the greatest profit, often involving analysis of marginal costs and marginal revenues.