A sample of birth weights of 34 girls was taken. Below are the results (in g):
3636.7 | 2713.6 | 3383.6 | 4315.3 | 3928.6 |
2338.8 | 3183.5 | 2982.3 | 3621.9 | 3022.7 |
2947.3 | 4022.8 | 3413.3 | 3728.8 | 3703.6 |
3808.7 | 3550 | 3938.5 | 3906.9 | 3374.3 |
2656.5 | 3735.8 | 4244.7 | 2568.6 | 3362.1 |
3552 | 3484.2 | 3150.5 | 3384.7 | 3508.4 |
3816.5 | 3469.9 | 2333.6 | 4426.7 |
(Note: The average and the standard deviation of the data are respectively 3447.5 g and 527.52 g.)
Use a 5% significance level to test the claim that the standard deviation of birthweights of girls is different from the standard deviation of birthweights of boys, which is 540 g.
Procedure:
Assumptions: (select everything that applies)
Step 1. Hypotheses Set-Up:
= | , where is 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 5% significance level we have sufficient evidence to reject the null hypothesis in favor of the alternative hypothesis.
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