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

question 24

True/False

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,there is sufficient evidence to conclude that the proportions between procedure A and procedure D are different at a 0.05 level of significance.

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Definitions:

Scalene

Refers to a group of three paired muscles in the lateral neck that facilitate breathing and are involved in various neck movements.

Closes the Anal Opening

This term likely refers to the sphincter ani externus muscle, which controls the opening and closing of the anus.

External Anal Sphincter

A muscle that controls the expulsion of feces from the anal canal.

External Urethral Sphincter

A muscle that controls the outflow of urine from the bladder and allows voluntary control over urination.