Dax Arias

Mathematics

18 October, 00:29

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.

High 6 9 9

Average 9 19 23

Low 7 8 10

Referring to the Table below, at α = 0.05 level of significance, what would be the decision rule?

a. Reject H_0 if chi-square > 16.919

b. Reject H_0 if chi-square > 15.507

c. Reject H_0 if chi-square > 11.143

d. Reject H_0 if chi-square > 9.488