A pharmaceutical company is about to launch a new manufacturing process in addition to the existing one. The quality control manager believes that the new method results in a different variation in the weights of the capsules. To verify the claim, the samples from each production line were obtained and the results are below (in mg):
Production Line 1:
100.5 | 98.6 | 101.3 | 103.6 | 95.7 |
103.3 | 102.9 | 99.6 | 99.9 | 100.8 |
104.9 | 101.6 | 101.1 | 101.6 | 96.5 |
(Note: The average and the standard deviation of the data are respectively 100.8 mg and 2.52 mg.)
Production Line 2:
99.9 | 97.9 | 100.3 | 97.9 | 101.5 |
97.4 | 97.4 | 100.3 | 96.4 | 101 |
98.6 | 98.7 |
(Note: The average and the standard deviation of the data are respectively 98.9 mg and 1.62 mg.)
Use a 10% significance level to test the claim that the standard deviation of the capsule weights in the production line 1 is greater than the standard deviation of the capsule weights in the production line 2.
Procedure:
Assumptions: (select everything that applies)
Step 1. Hypotheses Set-Up:
= | , where the and the units are |
, and the test is |
Step 2. The significance level %
Step 3. Compute the value of the test statistic: = (Round the answer to 3 decimal places)
Step 4. Testing Procedure: (Round the answers to 3 decimal places)
CVA | PVA |
Provide the critical value(s) for the Rejection Region: | Compute the P-value of the test statistic: |
left CV is and right CV is | P-value is |
Step 5. Decision:
CVA | PVA |
Is the test statistic in the rejection region? | Is the P-value less than the significance level? |
Conclusion:
Step 6. Interpretation:
At 10% significance level we have sufficient evidence to reject the null hypothesis in favor of the alternative hypothesis.
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