In: Statistics and Probability
The breaking strength of hockey stick shafts made of two different graphite-kevlar composites yields the following results (in Newtons):
Composite 1:
479 | 505.3 | 471.1 | 488.6 | 467.2 |
483.4 | 491.1 | 481.2 | 480.7 | 484.5 |
470.9 | 480 | 472.6 | 485.4 | 469.1 |
482.2 | 478.2 | 490.7 | 468.1 |
(Note: The average and the standard deviation of the data are respectively 480.5 Newtons and 9.6 Newtons.)
Composite 2:
506 | 521 | 474.4 | 496.6 | 517.5 |
506.3 | 511.3 | 486.9 | 499.3 | 466.4 |
507.3 | 527 |
(Note: The average and the standard deviation of the data are respectively 501.7 Newtons and 18.26 Newtons.)
Use a 10% significance level to test the claim that the standard deviation of the breaking strength of hockey stick shafts made of graphite-kevlar composite 1 is less than the standard deviation of the breaking strength of hockey stick shafts made of graphite-kevlar composite 2.
Procedure: Select an answer
Two proportions Z Hypothesis Test
Two means T (non-pooled) Hypothesis Test
Two paired means Z Hypothesis Test
Two means Z Hypothesis Test
Two variances F Hypothesis Test
Two means T (pooled) Hypothesis Test
Assumptions: (select everything that applies)
Step 1. Hypotheses Set-Up:
H0:H0: Select an answer μ μ₁-μ₂ p₁-p₂ σ₁²/σ₂² = |
where Select an answer p's are μ's are μ=μ₁-μ₂ is σ's are Select an answer population means difference between population means population proportions population standard deviations and the units are Select an answer Watt J N lbs |
Ha:Ha: Select an answer μ₁-μ₂ μ p₁-p₂ σ₁²/σ₂² and ≠ > < |
and the test is Select an answer Left-Tail Two-Tail Right-Tail |
Step 2. The significance level α=_____ %
Step 3. Compute the value of the test statistic: Select an answer (z₀ t₀ χ²₀ f₀) = ______(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? |
no or yes | no or yes |
Conclusion: Select an answer (Do not reject the null hypothesis in favor of the alternative. or Reject the null hypothesis in favor of the alternative.)
Step 6. Interpretation:
At 10% significance level we Select an answer (DO NOT or DO) have sufficient evidence to reject the null hypothesis in favor of the alternative hypothesis.
1.procedure:2 variances F hypothesis test.
2.Assumptions: 1.normal population
2.population standard deviation are unknown but assumed equal.
3.simple random samples.
4.independent samples.
3.Ho: . Units are :N(newton since breaking strength is a kind of force)
4.H1:. Left-tailed test.
5.significance level:=10%=0.10
6.value of test statistic:
The provided sample variances are
s12=333.42 and s22=92.16 and the sample sizes are given by n1=12 and n2=19
The F-statistic is computed as follows:
7.rejection region:
Based on the information provided, the significance level is α=0.10, and the the rejection region for this left-tailed test is
R={F:F<FL=1.912}.
8.p-value=0.993872
9.test-statistic=3.617>1.912 hence test statistic dienst lie in the reject kon region.
10.p-value=0.993872>0.10 no it is not less than the significance level.
11.do not reject the null hypothesis in favour of the alternative.
12At 10% significance level we do not have sufficient evidence to reject the null hypothesis in favour of the alternative hypothesis.
Please rate my answer and comment for doubts.