Concept explainers
Testing a Difference Other Than Zero Sometimes a researcher is interested in testing a difference in means other than zero. In Exercises 27 and 28, you will test the difference between two means using a null hypothesis of H0: μ1 − μ2 = k, H0: μ1 − μ2 ≥ k, or H0: μ1 − μ2 ≤ k. The standardized test statistic is still
27. Software Engineer Salaries Is the difference between the
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Elementary Statistics: Picturing the World (7th Edition)
- Testing Claims About Proportions. In Exercises 7–22, 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. Clinical Trials of OxyContin OxyContin (oxycodone) is a drug used to treat pain, but it is well known for its addictiveness and danger. In a clinical trial, among subjects treated with OxyContin, 52 developed nausea and 175 did not develop nausea. Among other subjects given placebos, 5 developed nausea and 40 did not develop nausea (based on data from Purdue Pharma L.P.). Use a 0.05 significance level to test for a difference between the rates of nausea for those treated with OxyContin and those given a placebo. a. Use a hypothesis test. b. Use an appropriate confidence interval. c. Does nausea appear to be an adverse reaction resulting from OxyContin?arrow_forwardTesting Claims About Proportions. In Exercises 7–22, 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. Denomination Effect A trial was conducted with 75 women in China given a 100-yuan bill, while another 75 women in China were given 100 yuan in the form of smaller bills (a 50-yuan bill plus two 20-yuan bills plus two 5-yuan bills). Among those given the single bill, 60 spent some or all of the money. Among those given the smaller bills, 68 spent some or all of the money (based on data from “The Denomination Effect,” by Raghubir and Srivastava, Journal of Consumer Research, Vol. 36). We want to use a 0.05 significance level to test the claim that when given a single large bill, a smaller proportion of women in China spend some or all of the money when compared to the proportion of women in China…arrow_forwardConduct a t-test at the .01 level. Find the correct decision about the null hypothesis. (A) Because the t-statistic exceeds the critical values, we fail to reject the null hypothesis. (B) Because the t-statistic exceeds the critical values, we reject the null hypothesis. (C) Because the t-statistic does not exceed the critical values, we fail to reject the null hypothesis. (D) Because the t-statistic does not exceed the critical values, we reject the null hypothesis.arrow_forward
- A statistical hypothesis is a statement about the numerical value of a population parameter. truefalse The test statistic is a numerical value, computed from the data, that the researcher uses to decide between the null and alternative hypotheses.truefalse The Null hypothesis, denoted by H0 represents the hypothesis that will be accepted only if the data provide convincing evidence of its truth.truefalsearrow_forwardTEST OF HYPOTHESISDirection: State when the error will be committed and give its possible consequences. An airline company does regular quality control checks on airplanes. One of them is tire inspection because tires are sensitive to the heat produced when the airplane runs through the runway. Since its operation, the company uses a particular type of tire which is guaranteed to perform even at a maximum surface temperature of 107oC. However, the tires cannot be used and need to be replaced when surface temperature exceeds a mean of 107oC. Help the company decide whether or not to do a complete tire replacement.arrow_forwardNational data reveals that the probability a youthful offender on probation will commit another crime is 80%. A special rehabilitation program was conducted for youthful offenders. A sample of 100 participants showed that 75 subsequently committed another crime. Do the hypothesis using the formal critical value method at 1% level of significance:H0: p ≥ 0.80H1: p < 0.80Remember to show your steps (including all relevant information) and explicitly verify that all assumptions of the procedure are satisfied. show the steps on how to solve it.arrow_forward
- Testing Claims About Proportions. In Exercises 7–22, 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. Does Aspirin Prevent Heart Disease? In a trial designed to test the effectiveness of aspirin in preventing heart disease, 11,037 male physicians were treated with aspirin and 11,034 male physicians were given placebos. Among the subjects in the aspirin treatment group, 139 experienced myocardial infarctions (heart attacks). Among the subjects given placebos, 239 experienced myocardial infarctions (based on data from “Final Report on the Aspirin Component of the Ongoing Physicians’ Health Study,” New England Journal of Medicine , Vol. 321: 129–135). Use a 0.05 significance level to test the claim that aspirin has no effect on myocardial infarctions. a. Test the claim using a hypothesis test. b.…arrow_forward(Upload the picture of your solutions. Follow the steps in Test of Hypothesis including your conclusion and round off the critical value and test statistic into 4 decimal places) It is believed that at least 60% of the residents in a certain area favor an annexation suit by a neighboring city. What conclusion would you draw if only 120 in a sample of 210 voters favor the suit? Use a 0.03 level of significance.arrow_forwardFormulation of Hypothesis: True or False. No need explanation 1. Type 2 error occurs when the null hypothesis is not rejected when in fact it is false. 2. The critical value for hypothesis test is a threshold to which value of the test statistic in a sample is compared determine or not the alternative hypothesis is rejected. 3. The level of significance is usually denoted by beta. it is related to the degree of certainty we require in order to reject null hypothesis in favor of the alternative hypothesis.arrow_forward
- Testing Claims About Proportions. In Exercises 7–22, 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. Ground vs. Helicopter for Serious Injuries 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…arrow_forwardTest the hypothesis using the P-value approach. Be sure to verify the requirements of the test. H0: p=0.4 versus H1: p>0.4 n=250; x=105, α=0.1 Use technology to find the P-value. P-value=_____?arrow_forwardA health officer is trying to study the malaria situation of Zambia. From the records of seasonal blood survey (SBS) results he came to understand that the proportion of people having malaria in Zambia was 3.8% in 2015. The size of the sample considered was 15,000. He also realized that during the year that followed (2016), blood samples were taken from 10,000 randomly selected persons. The result of the 2016 seasonal blood survey showed that 200 persons were positive for malaria. Help the Health officer in testing the hypothesis that the malaria situation of 2016 did not show any significant difference from that of 2015 (take the 5% level of significance).arrow_forward
- Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage