The Use of Carpeting in Hospitals, While Having Aesthetic Value

question 9

Multiple Choice

The use of carpeting in hospitals, while having aesthetic value, raises an obvious question: Are carpeted floors sanitary? An experiment comparing airborne bacteria levels in carpeted rooms with that in uncarpeted rooms was performed in an effort to answer this question. Specifically, for each of eight carpeted rooms and eight uncarpeted rooms in a hospital, the number of bacteria per cubic foot of air was measured. The data are given below. Assume that room sizes are equal, and that the 16 rooms in this experiment were assigned randomly to the carpet and no-carpet groups. If W, the Wilcoxon rank sum test statistic, is the sum of the ranks assigned to the carpeted group, then the value of W is:

• A)18.5.
• B)58.5.
• C)62.5.
• D)74.5.

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Definitions:

Absolute Value Inequality

An inequality that involves the absolute value of a variable expression and defines a range of solutions.

Solution

A quantity or array of quantities that solve an equation, inequality, or simultaneous equations.

Absolute Value

The distance of a number from zero on the number line, without considering direction; always a non-negative number.

Set Notation

A systematic way of writing sets, often using curly braces and symbols to define elements and operations on sets.