In 2005, the Terri Schiavo case focused national attention on the issue of withdrawal of life support from terminally ill patients or those in a vegetative state. A Harris Poll of 1010 U.S. adults was conducted by telephone on April 5–10, 2005. Of those surveyed, 140 had experienced the death of at least one family member or close friend within the last 10 years who died after the removal of life support. Find and interpret a 90% confidence interval for the proportion of all U.S. adults who had experienced the death of at least one family member or close friend within the last 10 years after life support had been withdrawn.
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following. a. Determine the sample proportion. b. Decide whether using the one-proportion z-test is appropriate. c. If appropriat
> The Quinnipiac University Poll conducts nationwide surveys as a public service and for research. This problem is based on the results of one such poll. Independent simple random samples of 300 residents each in red (predominantly Republican), blue (predo
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following. a. Determine the sample proportion. b. Decide whether using the one-proportion z-test is appropriate. c. If appropriat
> The U.S. Census Bureau compiles data on the U.S. population by region and race and publishes its findings in Current Population Reports. Independent simple random samples of residents in the four U.S. regions gave the following data on race. At the 1% si
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following. a. Determine the sample proportion. b. Decide whether using the one-proportion z-test is appropriate. c. If appropriat
> In the article “The Influence of Theme as Slot Machine Attribute on Casino Gamers Decision-Making” (American Journal of Applied Sciences, Vol. 10, No. 7, pp. 734–739), E. Wannenburg et al. explore the effects of theme on slot-machine gamers. Independent
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following. a. Determine the sample proportion. b. Decide whether using the one-proportion z-test is appropriate. c. If appropriat
> Self-concept can be defined as the general view of oneself in terms of personal value and capabilities. A study of whether visual impairment affects self-concept was reported in the article “An Exploration into Self Concept: A Comparative Analysis betwee
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following. a. Determine the sample proportion. b. Decide whether using the one-proportion z-test is appropriate. c. If appropriat
> A chi-square homogeneity test is to be conducted to decide whether four populations are nonhomogeneous with respect to a variable that has eight possible values. What are the degrees of freedom for the χ2-statistic?
> This exercise deals with truncated graphs. a. What is a truncated graph? b. Give a legitimate motive for truncating the axis of a graph. c. If you have a legitimate motive for truncating the axis of a graph, how can you correctly obtain that objective wi
> Explain the relationships among the sample proportion, the number of successes in the sample, and the sample size.
> Are the observed frequencies variables? What about the expected frequencies? Explain your answers.
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following. a. Determine the sample proportion. b. Decide whether using the one-proportion z-test is appropriate. c. If appropriat
> What is meant by saying that a variable has a chi-square distribution?
> In the February 2013 article “Offshore Drilling Support High as Deepwater Horizon Oil Spill Trial Opens,” E. Swanson reported on a HuffPost and YouGov poll that asked Americans what they think about increased offshore drilling for oil and natural gas. Of
> In a New York Times article “More Mothers Breast-Feed, in First Months at Least,” G. Harris reported that 77% of new mothers breast-feed their infants at least briefly, the highest rate seen in the United States in more than a decade. His report was base
> A Pew Internet & American Life Project examined Internet social networking. Among a sample of 929 online adults 18–29 years old, 836 said they use social networking sites. Determine a 95% confidence interval for the percentage of all online adults 18–29
> A poll by Gallup asked, “If you won 10 million dollars in the lottery, would you continue to work or stop working?” Of the 1039 American adults surveyed, 707 said that they would continue working. Obtain a 95% confidence interval for the proportion of al
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, a. use the one-proportion plus-four z-interval procedure to find the required confidence interval. b. compare your result with the corre
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, a. use the one-proportion plus-four z-interval procedure to find the required confidence interval. b. compare your result with the corre
> Give one reason why constructing and reading graphs and charts carefully is important.
> According to a study published in the Journal of the American Public Health Association, lefthanded people do not die at an earlier age than right-handed people, contrary to the conclusion of a highly publicized report done 2 years earlier. The investiga
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, a. use the one-proportion plus-four z-interval procedure to find the required confidence interval. b. compare your result with the corre
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, a. use the one-proportion plus-four z-interval procedure to find the required confidence interval. b. compare your result with the corre
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, a. use the one-proportion plus-four z-interval procedure to find the required confidence interval. b. compare your result with the corre
> For what is the phrase “number of failures” an abbreviation?
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, a. use the one-proportion plus-four z-interval procedure to find the required confidence interval. b. compare your result with the corre
> In discussing the sample size required for obtaining a confidence interval with a prescribed confidence level and margin of error, we made the following statement: “. . . we should be aware that, if the observed value of pˆ is closer to 0.5 than is our e
> In discussing the sample size required for obtaining a confidence interval with a prescribed confidence level and margin of error, we made the following statement: “If we have in mind a likely range for the observed value of pˆ, then, in light of Fig. 11
> What important theorem in statistics implies that, for a large sample size, the possible sample proportions of that size have approximately a normal distribution?
> A poll conducted by Gallup in December 2013 asked a sample of American adults whether they approved of the way President Obama was doing his job; 42% said yes, with a margin of error of plus or minus 3 percentage points. During that same time period, Qui
> On Thursday, June 13, 1996, then Arizona Governor Fife Symington was indicted on 23 counts of fraud and extortion. Just hours after the federal prosecutors announced the indictment, several polls were conducted of Arizonans asking whether they thought Sy
> One of the most important distributions in statistics is the standard normal distribution. a. Use the technology of your choice to generate a sample of 3000 observations from a variable that has the standard normal distribution. b. Use the technology of
> A company manufactures goods that are sold exclusively by mail order. The director of market research needed to test market a new product. She planned to send brochures to a random sample of households and use the proportion of orders obtained as an esti
> Refer to Exercise 11.54. a. Find the margin of error for the estimate of the percentage. b. Obtain a sample size that will ensure a margin of error of at most 5 percentage points for a 90% confidence interval without making a guess for the observed value
> Refer to Exercise 11.53. a. Find the margin of error for the estimate of the percentage. b. Obtain a sample size that will ensure a margin of error of at most 1.5 percentage points for a 99% confidence interval without making a guess for the observed val
> Refer to Exercise 11.52. a. Find the margin of error for the estimate of p. b. Obtain a sample size that will ensure a margin of error of at most 0.02 for a 95% confidence interval without making a guess for the observed value of pˆ. c. Find a 95% confid
> Regarding the phrase “number of successes”: a. For what is it an abbreviation? b. What symbol is used for it?
> Refer to Exercise 11.51. a. Determine the margin of error for the estimate of p. b. Obtain a sample size that will ensure a margin of error of at most 0.01 for a 95% confidence interval without making a guess for the observed value of pˆ. c. Find a 95% c
> According to the Internal Revenue Service, among people entitled to tax refunds, those who file online receive their refunds twice as fast as paper filers. A study conducted by International Communications Research (ICR) of Media, Pennsylvania, found tha
> In a nationwide survey, conducted by Pulse Opinion Research, LLC for Rasmussen Reports, a sample of American adults were asked whether they favor a plan to break up the 12 megabanks, which currently control about 69% of the banking industry; 50% of those
> The infant mortality rate (IMR) is the number of infant deaths per 1000 live births. Suppose that you have been commissioned to estimate the IMR in Singapore. From a random sample of 1109 live births in Singapore, you find that 0.361% of them resulted in
> Suppose that you have been hired to estimate the percentage of adults in your state who are literate. You take a random sample of 100 adults and find that 96 are literate. You then obtain a 95% confidence interval of or 0.922 to 0.998. From it you conclu
> In this exercise, use technology to work Exercise 2.159, as follows: a. Use the technology of your choice to obtain 50 random integers between 0 and 9. b. Use the technology of your choice to get a relative-frequency histogram based on single-value group
> During one year, Malaysia was the site of an encephalitis outbreak caused by the Nipah virus, a paramyxovirus that appears to spread from pigs to workers on pig farms. As reported by K. Goh et al. in the paper “Clinical Features of Nipah Virus Encephalit
> During one year, the U.S. Environmental Protection Agency reported that concentrated animal feeding operations (CAFOs) dump 2 trillion pounds of waste into the environment annually, contaminating the ground water in 17 states and polluting more than 35,0
> In a nationwide survey, conducted by Pulse Opinion Research, LLC for Rasmussen Reports, 1000 American adults were asked, among other things, whether they drink alcoholic beverages at least once a week; 38% said “yes.” Determine and interpret a 95% confid
> In the article “Explaining an Unusual Allergy,” appearing on the Everyday Health Network, Dr. A. Feldweg explained that allergy to sulfites is usually seen in patients with asthma. The typical reaction is a sudden increase in asthma symptoms after eating
> Regarding a sample proportion: a. What is it? b. What symbol is used for it?
> In a HuffPost Style and YouGov poll, 1000 U.S. adults were asked about their online vs. in-store clothes shopping. One finding was that 32% of respondents never clothes-shop online. Find and interpret a 95% confidence interval for the proportion of all U
> We have specified a margin of error, a confidence level, and a likely range for the observed value of the sample proportion. Obtain a sample size that will ensure a margin of error of at most the one specified (provided of course that the observed value
> We have specified a margin of error, a confidence level, and a likely range for the observed value of the sample proportion. Obtain a sample size that will ensure a margin of error of at most the one specified (provided of course that the observed value
> We have specified a margin of error, a confidence level, and a likely range for the observed value of the sample proportion. Obtain a sample size that will ensure a margin of error of at most the one specified (provided of course that the observed value
> This exercise can be done individually or, better yet, as a class project. a. Use a table of random numbers or a random-number generator to obtain 50 random integers between 0 and 9. b. Without graphing the distribution of the 50 numbers you obtained, gu
> We have specified a margin of error, a confidence level, and a likely range for the observed value of the sample proportion. Obtain a sample size that will ensure a margin of error of at most the one specified (provided of course that the observed value
> We have specified a margin of error, a confidence level, and a likely range for the observed value of the sample proportion. Obtain a sample size that will ensure a margin of error of at most the one specified (provided of course that the observed value
> We have specified a margin of error, a confidence level, and a likely range for the observed value of the sample proportion. Obtain a sample size that will ensure a margin of error of at most the one specified (provided of course that the observed value
> We have specified the margin of errors and confidence levels. Additionally, we have, in each case, provided an educated guess for the observed value of the sample proportion. For each exercise, a. obtain a sample size that will ensure a margin of error o
> We have specified the margin of errors and confidence levels. Additionally, we have, in each case, provided an educated guess for the observed value of the sample proportion. For each exercise, a. obtain a sample size that will ensure a margin of error o
> We have specified the margin of errors and confidence levels. Additionally, we have, in each case, provided an educated guess for the observed value of the sample proportion. For each exercise, a. obtain a sample size that will ensure a margin of error o
> Regarding a population proportion: a. What is it? b. What symbol is used for it?
> We have specified the margin of errors and confidence levels. Additionally, we have, in each case, provided an educated guess for the observed value of the sample proportion. For each exercise, a. obtain a sample size that will ensure a margin of error o
> We have specified the margin of errors and confidence levels. Additionally, we have, in each case, provided an educated guess for the observed value of the sample proportion. For each exercise, a. obtain a sample size that will ensure a margin of error o
> We have specified the margin of errors and confidence levels. Additionally, we have, in each case, provided an educated guess for the observed value of the sample proportion. For each exercise, a. obtain a sample size that will ensure a margin of error o
> Give an example, other than those presented in this section, of a a. qualitative variable. b. discrete, quantitative variable. c. continuous, quantitative variable.
> we have specified a margin of error and a confidence level. For each exercise, obtain a sample size that will ensure a margin of error of at most the one specified. margin of error = 0.04; confidence level = 99%
> we have specified a margin of error and a confidence level. For each exercise, obtain a sample size that will ensure a margin of error of at most the one specified. margin of error = 0.03; confidence level = 99%
> we have specified a margin of error and a confidence level. For each exercise, obtain a sample size that will ensure a margin of error of at most the one specified. margin of error = 0.01; confidence level = 90%
> we have specified a margin of error and a confidence level. For each exercise, obtain a sample size that will ensure a margin of error of at most the one specified. margin of error = 0.02; confidence level = 90%
> we have specified a margin of error and a confidence level. For each exercise, obtain a sample size that will ensure a margin of error of at most the one specified. margin of error = 0.02; confidence level = 95%
> we have specified a margin of error and a confidence level. For each exercise, obtain a sample size that will ensure a margin of error of at most the one specified. margin of error = 0.01; confidence level = 95%
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following tasks. a. Determine the sample proportion. b. Decide whether using the one-proportion z-interval procedure is appropria
> Is a population proportion a parameter or a statistic? What about a sample proportion? Explain your answers.
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following tasks. a. Determine the sample proportion. b. Decide whether using the one-proportion z-interval procedure is appropria
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following tasks. a. Determine the sample proportion. b. Decide whether using the one-proportion z-interval procedure is appropria
> In 1903, K. Pearson and A. Lee published the paper “On the Laws of Inheritance in Man. I. Inheritance of Physical Characters” (Biometrika, Vol. 2, pp. 357–462). The article examined and presented data on forearm length, in inches, for a sample of 140 men
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following tasks. a. Determine the sample proportion. b. Decide whether using the one-proportion z-interval procedure is appropria
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following tasks. a. Determine the sample proportion. b. Decide whether using the one-proportion z-interval procedure is appropria
> We have given the number of successes and the sample size for a simple random sample from a population. In each case, do the following tasks. a. Determine the sample proportion. b. Decide whether using the one-proportion z-interval procedure is appropria
> We have given a likely range for the observed value of a sample proportion p^. a. Based on the given range, identify the educated guess that should be used for the observed value of p to calculate the required sample size for a prescribed confidence leve
> We have given a likely range for the observed value of a sample proportion p^. a. Based on the given range, identify the educated guess that should be used for the observed value of p to calculate the required sample size for a prescribed confidence leve
> We have given a likely range for the observed value of a sample proportion p^. a. Based on the given range, identify the educated guess that should be used for the observed value of p to calculate the required sample size for a prescribed confidence leve
> We have given a likely range for the observed value of a sample proportion p^. a. Based on the given range, identify the educated guess that should be used for the observed value of p to calculate the required sample size for a prescribed confidence leve
> We have given a likely range for the observed value of a sample proportion p^. a. Based on the given range, identify the educated guess that should be used for the observed value of p to calculate the required sample size for a prescribed confidence leve
> Why is statistical inference generally used to obtain information about a population proportion?
> We have given a likely range for the observed value of a sample proportion p^. a. Based on the given range, identify the educated guess that should be used for the observed value of p to calculate the required sample size for a prescribed confidence leve
> A study by researchers at the University of Maryland addressed the question of whether the mean body temperature of humans is 98.6◦F. The results of the study by P. Mackowiak et al. appeared in the article “A Critical Appraisal of 98.6◦F, the Upper Limit
> According to an article in Science News, binge eating has been associated with a mutation of the gene for a brain protein called melanocortin 4 receptor (MC4R). In one study, F. Horber of the Hirslanden Clinic in Zurich and his colleagues genetically ana
> A Harris Poll asked Americans whether states should be allowed to conduct random drug tests on elected officials. Of 21,355 respondents, 79% said “yes.” a. Determine the margin of error for a 99% confidence interval. b. Without doing any calculations, in
> From the U.S. Census Bureau document America’s Families and Living Arrangements and an article in Time magazine, we found that, in 1963, 83.0% of American women between the ages of 25 and 54 were married, compared to 64.6% in 2010. a. For 2010, identify
> From Wikipedia’s on-line document “List of First Overall NBA Draft Picks,” we found that, since 1947, 10.4% of the number-one draft picks in the National Basketball Association have been other than U.S. nationals. a. Identify the population. b. Identify
> Prerequisite to this exercise are Exercises 11.9–11.13. What do your graphs in parts (c) of those exercises illustrate about the impact of increasing sample size on sampling error? Explain your answer. Data from Exercise 11.13: This exercise involves th
> Repeat Exercise 11.136 by applying the formula in Exercise 11.134(a) if you can reasonably presume that at most 41% of the men sampled and at most 49% of the women sampled will be people who sometimes order veg. Compare the results obtained in Exercise 1
> Refer to the study on ordering vegetarian. a. Without making a guess for the observed values of the sample proportions, find the common sample size that will ensure a margin of error of at most 0.01 for a 90% confidence interval. b. Find a 90% confidence
> Refer to the study on ordering vegetarian. a. Obtain the margin of error for the estimate of the difference between the proportions of men and women who sometimes order veg by taking half the length of the confidence interval found. Interpret your answer
> Suppose that you can make reasonably good educated guesses, pˆ1g and pˆ2g, for the observed values of pˆ1 and pˆ2. a. Use your result from Exercise 11.132 to show that a (1 − α)-level confidence interval for the difference between two population proporti
> Use your result from Exercise 11.132 to show that a (1 − α) level confidence interval for the difference between two population proportions that has a margin of error of at most E can be obtained by choosing rounded up to the nearest whole number.
> As reported by the U.S. Census Bureau in the document Educational Attainment in the United States, the percentage of adults in each state and the District of Columbia who have completed a bachelor’s degree is provided on the WeissStats site. a. use the t
> Obtain a formula for the margin of error, E, in estimating the difference between two population proportions by referring to Step 2 of Procedure.
