TABLE 12-10
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 12-10, 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 X² 16.919
B) Reject H₀ if X² 15.507
C) Reject H₀ if X² 11.143
D) Reject H₀ if X² 9.488

Question

TABLE 12-10
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 12-10, 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 X² > 16.919 
B) Reject H₀ if X² > 15.507 
C) Reject H₀ if X² > 11.143 
D) Reject H₀ if X² > 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 used in such a context (likely 4, given the options) is X² > 9.488.

TABLE 12-10 One Criterion Used to Evaluate Employees in the Assembly Section