TABLE 12-9
Four Surgical Procedures Currently Are Used

question 25

True/False

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 12-13, the null hypothesis cannot be rejected.

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Definitions:

Nasal Cavity

The large air filled space behind the nose, involved in respiration and sense of smell.

Larynx

The voice box or the area of the throat containing the vocal cords and used for breathing, swallowing, and speaking.

Pharynx

The muscular tube that serves as a pathway for the movement of food to the esophagus and air to the larynx.

Trachea

The windpipe, a tube connecting the larynx to the bronchi, allowing air flow to and from the lungs for respiration.