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Chapter 10: Q.8 (page 622)

Explain why the conditions for using two-sample z procedures to perform inference about p1-p2are not met in the settings

In-line skatersA study of injuries to in-line skaters used data from the National Electronic Injury Surveillance System, which collects data from a random sample of hospital emergency rooms. The researchers interviewed 161 people who came to emergency rooms with injuries from in-line skating. Wrist injuries (mostly fractures) were the most common.6The interviews found that 53people were wearing wrist guards and 6of these had wrist injuries. Of the 108who did not wear wrist guards, 45had wrist injuries.

Short Answer

Expert verified

The two-proportion z-test is not appropriate in this case.

Step by step solution

01

Step 1: Given Information

It is given in the question that, x1=6,n1=53,x2=45,n2=108

02

Explanation

The values are:

x1=6,n1=53,x2=45,n2=108

To perform the two-proportion z -test, the number of successes in both samples must be more than 10.

Here, success in the first sample is 6which is less than 10. It implies that the normality assumption is not fulfilled here.

Hence, the two-proportion z-test is not appropriate in this case.

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