Four Surgical Procedures Currently Are Used to Install Pacemakers $\quad$

question 203

Short Answer

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 4 procedures, and collects the following numbers of patients from their own records: $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$$\text { Procedure }$
$\begin{array}{l|cccc||c} & \text { A } & \text { B } & \text { C } & \text { D } & \text { Total } \\\hline \hline \text { Clear } & 27 & 41 & 21 & 7 & 96 \\\text { Return } & 11 & 15 & 9 & 11 & 46 \\\hline \hline \text { Total } & 38 & 56 & 30 & 18 & 142\end{array}$

Which of the following tests will be the most appropriate to find out whether the 4 procedures are equally effective?
a) $\chi ^ { 2 }$ test for difference in proportions.
b) $Z$ test for difference in proportions.
c) One-way ANOVA $F$ test for differences among more than two means
d) Kruskal-Wallis rank Test.

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Definitions:

Independent Variables

Factors in an experiment that are deliberately altered to test their impact on the variables being measured.

Manipulating Variables

The process of changing one or more variables in an experiment to observe the effects on other variables.

Double-Blind Procedure

A research method used to prevent bias, where neither the participants nor the experimenters know who is receiving a particular treatment.

Brand Effectiveness

Refers to the impact a brand has on its audience, including how well it achieves its marketing objectives and resonates with its target demographic.