The management of ABC Paper Corporation wants to determine whether there is a significant difference in the thickness of papers produced at their two existing plants. The following data has been accumulated for this test. The degrees of freedom (df) for this problem are given to be df = 80.
Plant 1 Plant 2
Sample Mean 30.8 30.0
Sample Standard Deviation 8.0 9.0
Sample Size 55 41
- What is the set of null and alternative hypotheses if we want to determine whether the thickness of papers produced at these two plants is the same?
- Using a level of significance of 0.05, what is the rejection rule for this test using the critical value approach?
- Calculate the t statistic
- Based on the above, what is the conclusion of this statistical test?