TABLE 9-1
Microsoft Excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is over 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the Microsoft Excel output for the sample of 46 cases:
n = 46; Arithmetic Mean = 28.00; Standard Deviation = 25.92; Standard Error = 3.82;
Null Hypothesis: H 0 : μ ≤ 20.000; α = 0.10; df = 45; T Test Statistic = 2.09;
One-Tail Test Upper Critical Value = 1.3006; p-value = 0.021; Decision = Reject.
-Referring to Table 9-1, the evidence proves beyond a doubt that the mean number of defective bulbs per case is over 20 during the morning shift.

Question

Quizplus · Accepted Answer

The evidence does not prove beyond a doubt; it only shows statistical significance at the 0.10 level, not absolute certainty.

TABLE 9-1 Microsoft Excel Was Used on a Set of Data Involving