TABLE 12-4
One Criterion Used to Evaluate Employees in the Assembly

TABLE 12-4
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.
$$\begin{array}{l}\text { \quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad Years Since Training Period }\\\begin{array} { r | r r c } &< 1\text { Year } & 1 - 4 \text { Years } & 5 \text { - 9Years } \\\hline \text { High } & 6 & 9 & 9 \\\text { Defect Rate: Average } & 9 & 19 & 23 \\\text { Low } & 7 & 8 & 10\end{array}\end{array}$$
-Referring to Table 12-4, which test would be used to properly analyze the data in this experiment to determine whether there is a relationship between defect rate and years of experience?

A) ?² test for differences among more than two proportions
B) Wilcoxon rank sum test for independent populations
C) Wilcoxon signed ranks test for two related populations
D) ?² test for independence