The EPA Has Stipulated That the Pollution Standard Index (PSI)

question 95

Multiple Choice

The EPA has stipulated that the Pollution Standard Index (PSI) for clean air standards is to average no more than 100. A random sample of nine days for the city of Acorn showed PSI readings of 144, 85, 90, 120, 150, 105, 93, 130, and 115. Assume the population of PSI readings is highly nonnormal. The EPA wants to determine if there is significant evidence to conclude that Acorn's air is dirtier than the stipulated clean air standards. Which one of the following tests is appropriate for this problem?

• A) Wilcoxon signed ranks test
• B) Wilcoxon rank sum test
• C) sign test
• D) Kruskal-Wallis test
• E) Spearman's rank correlation test

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Definitions:

Self-sealing

Characterizes materials or devices capable of automatically closing or repairing themselves after being punctured or cut.

Free Ends

The extremities or terminals of a linear structure, such as a piece of DNA or a thread, that are not attached or bonded to anything else.

Hydrophobic

Characteristic of molecules that repel water; substances that are not easily soluble in water.

Hydrophilic

A term describing molecules or substances that have an affinity for water, making them capable of dissolving in or being wetted by water.