TABLE 12-9
Four Surgical Procedures Currently Are Used to Install

question 57

Short Answer

TABLE 12-9
Four surgical procedures currently are used to install pacemakers. If the patient does not need to return for follow-up surgery the operation is called a "clear" operation. A heart center wants to compare the proportion of clear operations for the 4 procedures, and collects the following numbers of patients from their own records:
$$\begin{array}{l}\text {\quad\quad\quad\quad\quad\quad\quad Procedure }\\\begin{array} { l | r r r r | r } & \text { A } & \text { B } & \text { C } & \text { D } & \text { Total } \\\hline \text { Clear } & 27 & 41 & 21 & 7 & 96 \\\text { Return } & 11 & 15 & 9 & 11 & 46 \\\hline \text { Total } & 38 & 56 & 30 & 18 & 142\end{array}\end{array}$$ They will use this information to test for a difference among the proportion of clear operations using a chi-square test with a level of significance of 0.05.
-Referring to Table 12-9, the value of the test statistic is _____ .

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Definitions:

Derivative Security

A financial instrument whose value is dependent on the value of an underlying asset, such as options or futures.

Common Stock

A type of equity security that represents ownership in a corporation, giving holders voting rights and a share in the company's profits through dividends and/or capital appreciation.

Call Option

The right, but not the obligation, to buy an underlying asset at a specified strike price within a specified time frame.

Futures Contract

A binding contract to trade a certain commodity or financial asset at a fixed price, with the transaction set to occur on a specified date in the future.