Question

Two catalysts are being analyzed to determine how they affect the mean yield of a chemical process. Specifically, catalyst 1 is currently in use, but catalyst 2 is acceptable. Since catalyst 2 is cheaper, it should be adopted, providing it does not change the process yield. An experiment is run in the pilot plant and results in the data shown. (a) Is there any difference between the mean yields? Use α = 0.05 and assume equal variances. (b) Find the 100(1-α) % confidence interval for (µ1 - µ2). Use α = 0.05.

Observation number Catalyst 1 Catalyst 2

1 91.5 89.19

2 94.18 90.95

3 82.18 90.46

4 95.39 93.21

5 91.79 97.19

6 89.07 97.04

7 94.72 91.07

8 89.21 92.75

Answer 1

this is a paired sample t-test

Since we fail to reject the null hypothesis, we have no evidence that there is any difference between the mean yields.