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

question 100

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 critical value of the test is ________.

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Definitions:

National Average

This term typically refers to the average value or measurement found by aggregating specific data across an entire nation, often used in contexts such as test scores or income levels.

Surgical Site Infections

Infections that occur after surgery in the part of the body where the surgery took place, which can sometimes lead to serious complications.

National Average

The mean or median value of a particular measure computed from data collected across a nation.

Mean Distribution

Refers to the distribution of the arithmetic mean from multiple samples from the same population, often assumed to be normal in many statistical applications.