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:

Time Series

A sequence of data points, typically consisting of successive measurements made over a time interval.

Weighted Moving Average

A statistical method used to analyze data points by giving different weights to different data points, commonly used in stock market analysis and forecasting.

Record Keeping

The systematic process of creating, maintaining, and managing records or documents for the purpose of providing accurate evidence of business transactions and activities.

Simple Exponential Smoothing

A time series forecasting method for univariate data that considers the weighted sum of past observations, with the weights declining exponentially as the observations get older.