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

question 371

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 which of the 4 procedures is the most 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) The Marascuilo procedure.

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Definitions:

CSMA/CD

The method used on Ethernet networks to avoid data collisions; short for carrier sense multiple access with collision detection. A node connected to the network uses carrier sense to verify that no other nodes are currently transmitting data signals.

P2P

Stands for Peer-to-Peer, a decentralized communications model in which each party has the same capabilities and either party can initiate a communication session.

MAC Address

A distinctive identifier allocated to network interfaces for communication on the physical network section.

Collision Signals

Signals generated when two or more devices attempt to transmit over a network at the same time, resulting in a collision.