TABLE 11-10
One criterion used to evaluate employees in the assembly section of a large factory is the number of defective pieces per 1,000 parts produced. The quality control department wants to find out whether there is a relationship between years of experience and defect rate. Since the job is repetitious, after the initial training period, any improvement due to a learning effect might be offset by a loss of motivation. A defect rate is calculated for each worker in a yearly evaluation. The results for 100 workers are given in the table below.

-Referring to Table 11-10, find the rejection region necessary for testing at the 0.05 level of significance whether there is a relationship between defect rate and years of experience.
A) Reject H₀ if χ² 16.919.
B) Reject H₀ if χ² 15.507.
C) Reject H₀ if χ² 11.143.
D) Reject H₀ if χ² 9.488.

Question

TABLE 11-10
One criterion used to evaluate employees in the assembly section of a large factory is the number of defective pieces per 1,000 parts produced. The quality control department wants to find out whether there is a relationship between years of experience and defect rate. Since the job is repetitious, after the initial training period, any improvement due to a learning effect might be offset by a loss of motivation. A defect rate is calculated for each worker in a yearly evaluation. The results for 100 workers are given in the table below.
 
-Referring to Table 11-10, find the rejection region necessary for testing at the 0.05 level of significance whether there is a relationship between defect rate and years of experience.
A) Reject H₀ if χ² > 16.919. 
B) Reject H₀ if χ² > 15.507. 
C) Reject H₀ if χ² > 11.143. 
D) Reject H₀ if χ² > 9.488.

Quizplus · Accepted Answer

The rejection region for a chi-square test at the 0.05 level of significance with degrees of freedom typically associated with a 2x2 table is χ² > 9.488.

TABLE 11-10 One Criterion Used to Evaluate Employees in the Assembly Section