The report “The 2016 Consumer Financial Literacy Survey” (The National Foundation for Credit Counseling, www.nfcc.org, retrieved October 28, 2016) summarized data from a representative sample of 1668 adult Americans. Based on data from this sample, it was reported that over half of U.S. adults would give themselves a grade of A or B on their knowledge of personal finance. This statement was based on observing that 934 people in the sample would have given themselves a grade of A or B. a. Construct and interpret a 95% confidence interval for the proportion of all adult Americans who would give themselves a grade of A or B on their financial knowledge of personal finance. b. Is the confidence interval from Part (a) consistent with the statement that a majority of adult Americans would give themselves a grade of A or B? Explain why or why not.
> An article titled “tcU horned frogs game preview (part 1)” (www.uwdawgpound.com/2016/11/26/13710900 /washington-huskies-tcu-horned-frogs-game-preview-part-1, retrieved December 20, 2016) previews a college basketball g
> Researchers were interested in comparing regular- intensity exercise and high-intensity exercise for patients recovering from hospitalization due to chronic obstructive pulmonary disease (COPD). The researchers followed patients in Denmark who were enrol
> Example 11.3 describes the results of a survey of 1129 full-time college faculty and 293 part-time college faculty. Survey participants were asked if they require undergraduate students to submit papers through plagiarism-detection software; 40% of the f
> The article “rapid evolutionary response to a transmissible cancer in tasmanian Devils” (www.nature.com /articles/ncomms12684, retrieved December 20, 2016) describes the spread of devil facial tumor disease (DFTD), whi
> Women diagnosed with breast cancer whose tumors have not spread may be faced with a decision between two surgical treatments—mastectomy (removal of the breast) or lumpectomy (only the tumor is removed). In a long-term study of the effectiveness of these
> The article “Spray flu Vaccine may work better than injections for tots” (San Luis Obispo Tribune, May 2, 2006) described a study that compared flu vaccine administered by injection and flu vaccine administered as a nasal spray. Each of the 8000 children
> Women diagnosed with breast cancer whose tumors have not spread may be faced with a decision between two surgical treatments—mastectomy (removal of the breast) or lumpectomy (only the tumor is removed). In a long-term study of the effectiveness of these
> The article “fish oil Staves off Schizophrenia” (USA TODAY, february 2, 2010) describes a study in which 81 patients age 13 to 25 who were considered at risk for mental illness were randomly assigned to one of two groups. Those in one group took four fis
> In a study of a proposed approach for diabetes prevention, 339 people under the age of 20 who were thought to be at high risk of developing type I diabetes were assigned at random to one of two groups. One group received twice daily injections of a low d
> Some fundraisers believe that people are more likely to make a donation if there is a relatively quick deadline given for making the donation. The paper “now or never! the effect of Deadlines on charitable giving: evidence from two natural field experime
> Use the data given in the previous exercise to construct and interpret a 95% confidence interval estimate of the difference in the injury proportion for the traditional cleat treatment and the swivel disc shoe treatment.
> The article “footwear, traction, and the risk of athletic injury” (january 2016, www.lermagazine.com/article/footwear -traction-and-the-risk-of-athletic-injury, retrieved December 15, 2016) describes a study in which high school football players were giv
> Choice blindness is the term that psychologists use to describe a situation in which a person expresses a preference and then doesn’t notice when they receive something different than what they asked for. The authors of the paper “can chocolate cure blin
> The paper “passenger and cell phone conversations in Simulated Driving” (Journal of Experimental Psychology: Applied [2008]: 392–400) describes an experiment that investigated if talking on a cell phone while driving is more distracting than talking with
> Use the data given in the previous exercise to construct and interpret a 95% confidence interval estimate of the difference in the proportion experiencing pain relief for the surgery treatment and this proportion for the therapy treatment.
> In the experiment described in the article “Study points to benefits of Knee replacement Surgery over therapy alone” (The New York Times, October 21, 2015), adults who were considered candidates for knee replacement were followed for one year. Suppose th
> A headline that appeared in Woman’s World stated “black currant oil curbs hair Loss!” (Woman’s World, april 4, 2016). This claim was based on an experiment described in the paper “effect of a nutritional Supplement on hair Loss in women” (Journal of Cosm
> Gallup surveyed adult Americans about their consumer debt (“americans’ big Debt burden growing, not evenly Distributed,” february 4, 2016, www.gallup.com, retrieved December 15, 2016). They reported that 47% of millennials (those born between 1980 and 19
> The report referenced in the previous exercise also stated that the proportion who thought their parents would help with buying a house or renting an apartment for the sample of young adults was 0.37. For the sample of parents, the proportion who said th
> The report “Young people Living on the edge” (greenberg Quinlan rosner research, 2008) summarizes a survey of people in two independent random samples. One sample consisted of 600 young adults (age 19 to 35), and the other sample consisted of 300 parents
> The article referenced in the previous exercise also reported that 53% of the Republicans surveyed indicated that they were opposed to making women register for the draft. Would you use the large-sample test for a difference in population proportions to
> The article “most women oppose having to register for the Draft” (february 10, 2016, www.rasmussenreports. com, retrieved December 15, 2016) describes a survey of likely voters in the United States. The article states that 36% of those in a representativ
> The Interactive Advertising Bureau surveyed a representative sample of 1000 adult Americans and a representative sample of 1000 adults in China (“majority of Digital Users in U.S. and china regularly Shop and purchase via e-commerce,&ac
> The paper “on the nature of creepiness” (New Ideas in Psychology [2016]: 10–15) describes a study to investigate what people think is “creepy.” Each person in a sample of women and a sample of men were asked to do the following: Imagine a close friend o
> A hotel chain is interested in evaluating reservation processes. Guests can reserve a room by using either a telephone system or an online system that is accessed through the hotel’s web site. Independent random samples of 80 guests who reserved a room b
> In a survey of mobile phone owners, 53% of iPhone users and 42% of Android phone users indicated that they upgraded their phones at least every two years (“americans Split on how often they Upgrade their Smartphones,”
> Many people believe that they experience “information overload” in today’s digital world. The report “information overload” (pew research center, December 7, 2016) describes a survey in which people were asked if they feel overloaded by information. In a
> The Bureau of Labor Statistics report referenced in the previous exercise also reported that 7.3% of high school graduates were unemployed in October 2013 and 5.7% of high school graduates were unemployed in October 2014. Suppose that the reported percen
> The bureau of Labor Statistics (www.bls.gov/opub /ted/2014/ted_20141112.htm, retrieved December 13, 2016) reported that 3.8% of college graduates were unemployed in October 2013 and 3.1% of college graduates were unemployed in October 2014. Suppose that
> The article “more teen Drivers See marijuana as oK; it’s a Dangerous trend” (USA TODAY, February 23, 2012) describes two surveys of U.S. high school students. One survey was conducted in 2009 and the other was conducted in 2011. In 2009, 78% of the peopl
> A survey of high school students is described in the report “Students on Stem” (changetheequation.org/students -stem, retrieved December 12, 2016). The report states that 14% of those in a sample of students in low-income households (defined as a househo
> The report “the new food fights: U.S. public Divides over food Science” (December 1, 2016, www.pewinternet.org, retrieved December 10, 2016) states that younger adults are more likely to see foods with genetically modified ingredients as being bad for th
> The following graphical display is similar to one that appeared in USA TODAY (february 16, 2012). The display summarizes data from surveys of male and female American adults. Assume that the two samples were independently selected representative samples
> A Harris Poll press release dated November 1, 2016 summarized results of a survey of 2463 adults and 510 teens age 13 to 17 (“american teens no Longer more Likely than adults to believe in god, miracles, heaven, jesus, angels, or the Devil,” www.theharri
> The U.S. Department of Transportation reported that in a large study of mobile phone use while driving conducted in 2015, 4.4% of female drivers observed and 3.5% of male drivers observed were using a handheld mobile phone while driving (“traffic Safety
> According to the U.S. census bureau (www.census.gov), the percentage of U.S. residents living in poverty in 2015 was 12.2% for men and 14.8% for women. These percentages were estimates based on data from large representative samples of men and women. Sup
> An article titled “The Latest on Workplace Monitoring and Surveillance” (American Management Association, November 17, 2014) referred to the “2007 Electronic Monitoring & Surveillance Survey.” In a summary of survey results submitted by 304 U.S. business
> The article “Report: More Than Half of DC-Area Millennials Are Using Ride-Hailing Apps” (June 23, 2016, www .washingtonian.com/2016/06/23/report-half-dc-area -millennials-using-ride-hailing-apps/, retrieved May 4, 2017
> A survey on SodaHead (www.sodahead.com/survey /featured/anonymous-advice/?results51, retrieved May 13, 2016) reported that 603 out of 753 respondents replied “no” to the question “Should you be friend
> USA TODAY (January 24, 2012) reported that ownership of tablet computers and e-readers is soaring. Suppose you want to estimate the proportion of students at your college who own at least one tablet or e-reader. What sample size would you use in order to
> Data from a representative sample were used to estimate that 32% of all computer users in 2011 had tried to get on a Wi-Fi network that was not their own in order to save money (USA TODAY, May 16, 2011). You decide to conduct a survey to estimate this pr
> In spite of the potential safety hazards, some people would like to have an Internet connection in their car. A preliminary survey of adult Americans has estimated the proportion of adult Americans who would like Internet access in their car to be somewh
> The 1991 publication of the book Final Exit, which includes chapters on doctor-assisted suicide, caused a great deal of controversy in the medical community. The Society for the Right to Die and the American Medical Association quoted very different figu
> The article “Should Canada Allow Direct-to-Consumer Advertising of Prescription Drugs?” (Canadian Family Physician [2009]: 130–131) calls for the legalization of advertising of prescription drugs in Canada. Suppose you wanted to conduct a survey to estim
> A manufacturer of small appliances purchases plastic handles for coffeepots from an outside vendor. If a handle is cracked, it is considered defective and can’t be used. A large shipment of plastic handles is received. How many handles from the shipment
> In 2010, the online security firm Symantec estimated that 63% of computer users don’t change their passwords very often (www.cnet.com/news/survey-63-dont -change-passwords-very-often, retrieved November 19, 2016). Because this estimate may be outdated, s
> A discussion of digital ethics appears in the article “Academic Cheating, Aided by Cell Phones or Web, Shown to be Common” (Los Angeles Times, June 17, 2009). One question posed in the article is: What proportion of college students have used cell phones
> The report referenced in the previous exercise also indicated that 33% of those in a representative sample of 533 homeowners in southern states said that they had considered installing solar panels. a. Use the given information to construct and interpre
> The report “The Politics of Climate” (Pew Research Center, October 4, 2016, www.pewinternet.org/2016/10/04 /the-politics-of-climate, retrieved May 6, 2017) summarized data from a survey on public opinion of renewable and other energy sources. It was repo
> The article referenced in the previous exercise also indicated that 811 of the 1001 students surveyed said that they would feel restricted if they could only work on digital devices. Would a 95% confidence interval for the proportion of students age 13 t
> The article “Write It by Hand to Make It Stick” (Advertising Age, July 27, 2016) summarizes data from a survey of 1001 students age 13 to 19 years. Of the students surveyed, 851 reported that they learn best using a mix of digital and nondigital tools. C
> One thousand randomly selected adult Americans participated in a survey conducted by the Associated Press (June 2006). When asked “Do you think it is sometimes justified to lie, or do you think lying is never justified?” 52% responded that lying was neve
> In 2010, the National Football League adopted new rules designed to limit head injuries. In a survey conducted in 2015 by the Harris Poll, 1216 of 2096 adults indicated that they were football fans and followed professional football. Of these football fa
> The article “Most Dog Owners Take More Pictures of Their Pet Than Their Spouse” (August 22, 2016, news.fastcompany.com/most-dog-owners-take-more-pictures-oftheir-pet-than-their-spouse-4017458, retrieved May 6, 2017) indicates that in a sample of 1000 dog
> The report “Job Seeker Nation Study 2016” (www .jobvite.com/wp-content/uploads/2016/03/Jobvite _Jobseeker_Nation_2016.pdf, retrieved May 6, 2017) summarized a survey of 2305 working adults. The report indicates that 484 of the working adults surveyed sai
> The USA Snapshot titled “Social Media Jeopardizing Your Job?” (USA TODAY, November 12, 2014) summarized data from a survey of 1855 recruiters and human resource professionals. The Snapshot indicted that 53% of the people surveyed had reconsidered a job c
> For the situation described in the previous exercise, use the five-step process for estimation problems (EMC3) to construct and interpret a 99% confidence interval for the proportion of mothers of children under the age of 2 years who post pictures of th
> The USA Snapshot titled “Baby’s First Photo Reveal” (USA TODAY, October 17, 2014) summarized data from a survey of 1001 mothers with children under the age of 2. The Snapshot includes the following statement: “83% of moms post new baby photos from the de
> The formula used to calculate a large-sample confidence interval for p is What is the appropriate z critical value for each of the following confidence levels? a. 95% b. 98% c. 85% P(1 – p) p + (z critical value)\
> Appropriate use of the interval requires a large sample. For each of the following combinations of n and p ˆ, indicate whether the sample size is large enough for this interval to be appropriate. a. n = 100 and p ˆ = 0.70 b. n =
> Based on data from a survey of 1200 randomly selected Facebook users (USA TODAY, March 24, 2010), a 98% confidence interval for the proportion of all Facebook users who say it is OK to ignore a coworker’s “friend” request is (0.35, 0.41). What is the mea
> For each of the following choices, explain which would result in a narrower large-sample confidence interval for p: a. 95% confidence level or 99% confidence level b. n = 200 or n = 500
> Suppose that a campus bookstore manager wants to know the proportion of students at the college who purchase some or all of their textbooks online. Two different people independently selected random samples of students at the college and used their sampl
> It probably wouldn’t surprise you to know that Valentine’s Day means big business for florists, jewelry stores, and restaurants. But did you know that it is also a big day for pet stores? In January 2015, the National Retail Federation conducted a survey
> In a survey of 800 college students in the United States, 576 indicated that they believe that a student or faculty member on campus who uses language considered racist, sexist, homophobic, or offensive should be subject to disciplinary action (“Listenin
> The Princeton Review 2016 College Hopes and Worries Survey Report (www.princetonreview.com/cms-content/final_cohowo2016survrpt.pdf, retrieved May 6, 2017) reported that 31% of students applying to college wanted to attend a college that was within 250 mi
> For the study described in the previous exercise, use the five-step process for estimation problems (EMC3) to construct and interpret a 95% confidence interval for the proportion of hiring managers and human resource professionals who use social network
> The article “Career Expert Provides DOs and DON’Ts for Job Seekers on Social Networking” (CareerBuilder.com, August 19, 2009) included data from a survey of 2667 hiring managers and human resource professionals. The article noted that more employers are
> The formula used to calculate a large-sample confidence interval for p is What is the appropriate z critical value for each of the following confidence levels? a.90% b. 99% c. 80% P(1 – p) p + (z critical value)\
> Appropriate use of the interval requires a large sample. For each of the following combinations of n and p ˆ, indicate whether the sample size is large enough for this interval to be appropriate. a. n = 50 and p ˆ = 0.30 b. n =
> Based on data from a survey of 1200 randomly selected Facebook users (USA TODAY, March 24, 2010), a 95% confidence interval for the proportion of all Facebook users who say it is OK for someone to “friend” his or her boss is (0.41, 0.47). What is the mea
> For each of the following choices, explain which one would result in a wider large-sample confidence interval for p: a. 90% confidence level or 95% confidence level b. n = 100 or n = 400
> Suppose that a city planning commission wants to know the proportion of city residents who support installing streetlights in the downtown area. Two different people independently selected random samples of city residents and used their sample data to co
> An article in the Chicago Tribune (August 29, 1999) reported that in a poll of residents of the Chicago suburbs, 43% felt that their financial situation had improved during the past year. The following statement is from the article: “The findings of this
> Business Insider reported that a study commissioned by eBay Motors found that nearly 40% of millennials who drive a car that is more than 5 years old have named their cars (“Millennials Have an Odd Habit When It Comes to Their Cars,” April 14, 2016). a.
> The USA Snapshot titled “Have a Nice Trip” (USA TODAY, November 17, 2015) summarized data from a survey of 1000 U.S. adults who had traveled by air at least once in the previous year. The Snapshot includes the following statement: “38% admit to yelling a
> The article “Most Americans Don’t Understand the Cloud, But They Should” (foxbusiness.com, October 17, 2016, retrieved November 12, 2016) reported that in a sample of 1000 people, 22% said they have pretended to know what the cloud is or how it works. As
> USA TODAY reported that the proportion of Americans who prefer cheese on their burgers is 0.84 (USA TODAY, September 7, 2016). This estimate was based on a survey of a representative sample of 1000 adult Americans. Calculate and interpret a margin of err
> Suppose that 935 smokers each received a nicotine patch, which delivers nicotine to the bloodstream at a much slower rate than cigarettes do. Dosage was decreased to 0 over a 12-week period. Of these 935 people, 245 were still not smoking 6 months after
> The USA Snapshot titled “Big Bang Theory” (USA TODAY, October 14, 2016) summarized data from a sample of 1003 American parents of children age 6 to 11 years. It reported that 53% of these parents view science-oriented TV shows as a good way to expose the
> The use of the formula for margin of error requires a large sample. For each of the following combinations of n and pˆ, indicate whether the sample size is large enough for use of this formula to be appropriate. a. n = 100 and pˆ = 0.70 b. n = 40 and
> The report “Parents, Teens and Digital Monitoring” (Pew Research Center, January 7, 2016, www.pewinternet .org/2016/01/07/parents-teens-and-digital-monitoring, retrieved May 5, 2017) reported that 61% of parents of teens aged 13 to 17 said that they had
> Consider taking a random sample from a population with p 5 0.70. a. What is the standard error of p ˆ for random samples of size 100? b. Would the standard error of pˆ be smaller for samples of size 100 or samples of size 400? c. Does decreasing the s
> A car manufacturer is interested in learning about the proportion of people purchasing one of its cars who plan to purchase another car of this brand in the future. A random sample of 400 of these people included 267 who said they would purchase this bra
> The report “The 2016 Consumer Financial Literacy Survey” (The National Foundation for Credit Counseling, www .nfcc.org, retrieved October 28, 2016) summarized data from a representative sample of 1668 adult Americans. When asked if they typically carry c
> The paper “Sleeping with Technology: Cognitive, Affective and Technology Usage Predictors of Sleep Problems Among College Students” (Sleep Health [2016]: 49–56) summarized data from a survey of a sample of college students. Of the 734 students surveyed,
> The use of the formula for margin of error requires a large sample. For each of the following combinations of n and pˆ, indicate whether the sample size is large enough for use of this formula to be appropriate. a. n = 50 and p ˆ = 0.30 b. n = 50 and p
> The report “2007 Electronic Monitoring & Surveillance Survey” (American Management Association) summarized a survey of 304 U.S. businesses. The report stated that 91 of the 304 businesses had fired workers for misuse of the Internet. Assume that this sam
> Consider taking a random sample from a population with p = 0.40. a. What is the standard error of pˆ for random samples of size 100? b. Would the standard error of pˆ be greater for samples of size 100 or samples of size 200? c. If the sample size wer
> A large online retailer is interested in learning about the proportion of customers making a purchase during a particular month who were satisfied with the online ordering process. A random sample of 600 of these customers included 492 who indicated they
> A researcher wants to estimate the proportion of property owners who would pay their property taxes one month early if given a $50 reduction in their tax bill. Would the standard error of the sample proportion pˆ be larger if the actual population propor
> A researcher wants to estimate the proportion of city residents who favor spending city funds to promote tourism. Would the standard error of the sample proportion pˆ be smaller for random samples of size n = 100 or random samples of size n = 200?
> A random sample will be selected from the population of all students enrolled at a large college. The sample proportion pˆ will be used to estimate p, the proportion of all students who use public transportation to travel to campus. For which of the foll
> If two statistics are available for estimating a population characteristic, under what circumstances might you choose a biased statistic over an unbiased statistic?
> A random sample will be selected from the population of all adult residents of a particular city. The sample proportion pˆ will be used to estimate p, the proportion of all adult residents who do not own a car. For which of the following situations will
> Use the formula for the standard error of pˆ to explain why increasing the sample size decreases the standard error.
> A researcher wants to estimate the proportion of students enrolled at a university who are registered to vote. Would the standard error of the sample proportion pˆ be larger if the actual population proportion was p = 0.4 or p = 0.8?
> Three different statistics are being considered for estimating a population characteristic. The sampling distributions of the three statistics are shown in the following illustration: Which statistic would you recommend? Explain your choice. Statist
> Three different statistics are being considered for estimating a population characteristic. The sampling distributions of the three statistics are shown in the following illustration: Which of these statistics are unbiased estimators of the population c
> For estimating a population characteristic, why is an unbiased statistic generally preferred over a biased statistic? Does unbiasedness alone guarantee that the estimate will be close to the actual value of the population characteristic? Explain.
