Concept explainers
The U.S. Department of Transportation requires tire manufactures to provide performance on tire sidewalls to help prospective buyers make their purchasing decisions. One very important place of information is the tread wear index, which indicates the tire’s resistance of tread wear. A tire with a grade of 200 should last twice as long, on average, as a tire with a grade of 100.
A consumer organization wants to test the actual tread wear index of a brand name of tires that claims “graded 200� on the sidewall of the tire. A random sample of
a. Is three evidence that the population mean tread wear index is different from 200? (Use a 0.05 level of significance.)
b. Determine the p-value and interpret its meaning.
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
Basic Business Statistics, Student Value Edition (13th Edition)
- Find the mean hourly cost when the cell phone described above is used for 240 minutes.arrow_forwardName the four characteristics of a good definition.arrow_forwardA researcher evaluates a new cholesterol medication by measuring cholesterol levels for a group of patients before they begin taking the medication and after they have been taking the medication for 8 weeks. A second researcher measures quality of life for a group of 40-year-old men who have been married for at least 5 years and a group of 40-year-old men who are still single. Explain why the first researcher is probably not concerned about the validity of the measurement, whereas the second researcher probably is. (Hint: What variable is each researcher measuring and how will it be measured?)arrow_forward
- The Environmental Protection Agency (EPA) uses a measure called the Pollutant Standards Index (PSI) to measure air quality in a city. A PSI reading over 100 indicates a day when the air quality is considered unhealthy. The measurements represent the number of days in 1995 that the PSI was over 100 for twenty metropolitan areas in the U.S. Midwest. 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 3, 4, 4, 4, 4, 5, 7, 7, 11, 14 Which of the above is the appropriate boxplot for this data?AB C When we drew the boxplot for this data we found no extreme outliers:truefalsearrow_forwardAn insurance company hires an actuary to determine whether the number of hours of safety drivingclasses can be used to predict the number of driving accidents for each driver. Identify theexplanatory variable, if any.arrow_forwardOne of the categories of special education are children who are diagnosed with Speech/Language Impairment (SLI). The most common SLI diagnosis is dyslexia. A major difficulty for children with this diagnosis of dyslexia surrounds the skills of reading. A special education teacher is interested in knowing whether a new reading technique increases reading skills for children diagnosed with dyslexia. She uses the WRAT as a way of measuring reading skills and the average for this test is 55 with a standard deviation of 4.5. She takes a random sample of 125 children diagnosed with dyslexia, employs her reading program with them and finds their mean on the WRAT to be 56.1. Test the null hypothesis at the .05 level of significance.arrow_forward
- he Environmental Protection Agency (EPA) uses a measure called the Pollutant Standards Index (PSI) to measure air quality in a city. A PSI reading over 100 indicates a day when the air quality is considered unhealthy. The measurements represent the number of days in 1995 that the PSI was over 100 for twenty metropolitan areas in the U.S. Midwest.0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 3, 4, 4, 4, 4, 5, 7, 7, 11, 14A careless employee originally recorded a number that was at least 20 times larger than 14:0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 3, 4, 4, 4, 4, 5, 7, 7, 11, (much larger than 14)The employee's mistake would have the following effect:The median would stay the sameincrease decrease The mean would decreaseincrease stay the same The mode would increasestay the same decrease The IQR would increasedecrease stay the same The standard deviation would decreaseincrease stay the samearrow_forwardWhat does ∆2xk equal?arrow_forwardThis problem is fill in the blank. Just choose the correct answers. Thank you for your help. I posted the problem and wrote it out because the drop-down boxes probably will not work. A researcher studying stress is interested in the blood pressure measurements of chief executive officers (CEOs) of major corporations. He believes that the mean systolic blood pressure, μ, of CEOs of major corporations is different from 130 mm Hg, which is the value reported in a possibly outdated journal article. He plans to perform a statistical test. He measures the systolic blood pressures of a random sample of CEOs of major corporations and finds the mean of the sample to be 122 mm Hg and the standard deviation of the sample to be 16 mm Hg. Based on this information, answer the questions below. What are the null hypothesis (H0) and the alternative hypothesis (H1) that should be used for the test? H0: (choose one) less than, less than or equal to, greater than, greater than or equal to,…arrow_forward
- Suppose you as a researcher have collected data on wages, education, experiences and gender. In addition, you also asked the information on whether the respondent graduated from local or overseas university. Write a model that would allow you to test whether graduates from overseas university has different effect on wages between male and female. Describe the proxies and unit of measurement you use for the variables in the model.arrow_forwardWeotherwise is a magazine published by the American Mctcorological Socicty. One issue gives a rating system used to classify Nor'easter storms that froquently hit New England and can cause much damage near the occan. A severe storm has an average peak wave height of g = 16.4 feet for waves hitting the shore. Suppose that a Nor'easter is in progress at the severe storm class rating. Peak wave heights are usually measured from land (using binoculars) oft tixed cament plers. Suppose that a reading of 35 waves showed an zverage wave height of x- 17.3 foet. Pravlous studies of severe storms indilcate that o- 3.5 foet. Doas this information suggost that the storm is (perhaps tamporarily) Increasing above the severe rating? Usa a - 0.01. (a) What is the levcl of significance? .01 State the null and altarnate hypothesas. O Ho: H - 16.4 t; H 10.4 t; H: - 16.4 t O Ho: H 10.4 ft; H: - 10.4 ft O Ho: H - 10.1 ft; H:+ 10.1 t * Ho: H = 10.1 ft; H:> 16.1 ft (b) What sampling distrihutian will you…arrow_forwardThe Us food and Drug administration has a limit for mercury content in fish of 1.0ppm (parts per million) while in Canada the limit is 0.5 ppm. Using the variable average mercury in the Florida lakes dataset to test whether there is evidence that average mercury level of fish ( large mouth Bass) in Florida lakes is less than 1.0ppm and whether there is evidence that average mercury level of fish in Florida lakes is less than 0.5ppm. STATE THE NULL AND ALTERNATIVE HYPOTHESES? GIVE THE TEST STATISTICS AND P-VALUE? round the test statistic to two decimal places and the p-value to three decimal places. DOES THIS SAMPLE PROVIDE EVIDENCE THAT THE AVERAGE MERCURY LEVEL OF FISH (LARGE MOUTH BASS) IN FLORIDA LAKES IS LESS THAN 1.0PPM? LESS THAN 0.5 PPM : STATE THE NULL AND ALTERNATIVE HYPOTHESES. GIVE THE TEST STATISTICS AND P-VALUE ? round the test statistic to two decimal places and the p-value to three decimal places. DOES THIS SAMPLE PROVIDE EVIDENCE THAT THE AVERAGE MERCURY…arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin HarcourtCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALElementary Geometry For College Students, 7eGeometryISBN:9781337614085Author:Alexander, Daniel C.; Koeberlein, Geralyn M.Publisher:Cengage,