Instruction 15-8
Four Surgical Procedures Currently Are Used to Install

question 5

Short Answer

Instruction 15-8
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 centre wants to compare the proportion of clear operations for the four procedures,and collects the following numbers of patients from their own records:
| Procedure |
$$\begin{array} { | l | c | c | c | c | c | } \hline & \mathrm { A } & \mathrm { B } & \mathrm { C } & \mathrm { D } & \text { Total } \\\hline \text { Clear } & 27 & 41 & 21 & 7 & 96 \\\hline \text { Return } & 11 & 15 & 9 & 11 & 46 \\\hline \text { Total } & 38 & 56 & 30 & 18 & 142 \\\hline\end{array}$$ They will use this information to test for a difference among the proportion of clear operations using a chi-square test with a 0.05 level of significance.
-Referring to Instruction 15-8,the overall or mean proportion of clear operations is ________.

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Definitions:

Subcontractors

Individuals or companies hired by a primary contractor to perform specific parts of a larger project.

General Contractor

A principal contractor who is responsible for the oversight of a construction project, managing subcontractors, and providing materials and labor for the completion of the job.

Holdback

A portion of funds or payment deliberately kept back until certain conditions are met or work is completed satisfactorily.

Fraudulent Preferences

Financial transactions made by a debtor before bankruptcy that unfairly favor one creditor over others.