A team of eye surgeons has developed a new technique for a risky eye operation to restore the sight of people blinded from a certain disease. Under the old method, it is known that only 30% of the patients who undergo this operation recover their eyesight. Suppose that surgeons in various hospitals have performed a total of 225 operations using the new method and that 88 have been successful (i.e., the patients fully recovered their sight). Can we justify the claim that the new method is better than the old one? (Show all four steps of the hypothesis test. Use a 1% significance level.) (a) Hypothesize Null hypothesis: Alternative hypothesis: (b) Prepare, CLT: 1. random (assume it is) 2. Large sample, show calculations: 3. Large population (check) (c) Compute to compare, show calculator test name and output z-score: & p-value: (d) Interpret below.
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30) Alternative hypothesis: The percentage of successful surgeries using the new method is greater than the old method (μ > 0.30) ** Show more…
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A team of eye surgeons has developed a new technique for risky eye operations. Under the old method, it is known that only 30% of the patients who undergo this operation recover their eyesight. Suppose that surgeons in various hospitals have performed a total of 225 operations using the new method and that 88 have been successful. Can we justify the claim that the new method is better than the old one at 1% level of significance? STEPS: Population characteristics of interest: Null Hypothesis: Ho: Alternate Hypothesis: Ha: Significance Level: a= Test Statistics and its assumptions: Calculation of test statistics: P-Value and Conclusion:
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Decade old study
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Test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, P-value or critical value(s), then state the conclusion about the null hypothesis, as well as the final conclusion that addresses the original claim. A study investigated rates of fatalities among patients with serious traumatic injuries. Among 61,909 patients transported by helicopter, 7813 died. Among 161,566 patients transported by ground services, 17,775 died (based on data from "Association Between Helicopter vs Ground Emergency Medical Services and Survival for Adults With Major Trauma," by Galvagno et al., Journal of the American Medical Association, Vol. $307,$ No. 15 ). Use a 0.01 significance level to test the claim that the rate of fatalities is higher for patients transported by helicopter. a. Test the claim using a hypothesis test. b. Test the claim by constructing an appropriate confidence interval. c. Considering the test results and the actual sample rates, is one mode of transportation better than the other? Are there other important factors to consider?
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