TABLE 10-13
A quality control engineer is in charge of the manufacture of computer disks. Two different processes can be used to manufacture the disks. He suspects that the Kohler method produces a greater proportion of defects than the Russell method. He samples 150 of the Kohler and 200 of the Russell disks and finds that 27 and 18 of them, respectively, are defective. If Kohler is designated as "Group 1" and Russell is designated as "Group 2," perform the appropriate test at a level of significance of 0.01.
-Referring to Table 10-13, the null hypothesis should be rejected.

Question

Quizplus · Accepted Answer

According to Table 10-13, at a significance level of 0.01 and degrees of freedom of 1, the critical value of chi-square is 6.63. The calculated value of chi-square for this test is 7.84. Since the calculated value is greater than the critical value, we reject the null hypothesis and conclude that there is a significant difference in the proportion of defects produced by the two methods. Therefore, the answer is A, true.

TABLE 10-13 A Quality Control Engineer Is in Charge of the Manufacture