In 2016, the national foundation for credit counseling released a report titled “the 2016 consumer financial Literacy Survey” (www.nfcc.org, retrieved December 1, 2016). In a nationally representative sample of 1668 adult Americans, 965 indicated that they had checked their credit score within the last 12 months. Is there convincing evidence that a majority of adult Americans have checked their credit scores within the last 12 months? Test the relevant hypotheses using = 0.05.
> Describe the two types of errors that might be made when a hypothesis test is carried out.
> Medical personnel are required to report suspected cases of child abuse. Because some diseases have symptoms that are similar to those of child abuse, doctors who see a child with these symptoms must decide between two competing hypotheses: H0: symptoms
> An automobile manufacturer is considering using robots for part of its assembly process. Converting to robots is expensive, so it will be done only if there is strong evidence that the proportion of defective installations is less for the robots than for
> A manufacturer of handheld calculators receives large shipments of printed circuits from a supplier. It is too costly and time-consuming to inspect all incoming circuits, so when each shipment arrives, a sample is selected for inspection. A shipment is d
> Suppose that for a particular hypothesis test, the consequences of a Type I error are not very serious, but there are serious consequences associated with making a Type II error. Would you want to carry out the test using a small significance level a (su
> One type of error in a hypothesis test is failing to reject a false null hypothesis. What is the other type of error that might occur when a hypothesis test is carried out?
> The paper “breast mri as an adjunct to mammography for breast cancer Screening in high-risk patients” (American Journal of Roentgenology [2015]: 889–897) describes a study that investigated the useful
> A television manufacturer states that at least 90% of its TV sets will not need service during the first 3 years of operation. A consumer group wants to investigate this statement. A random sample of n = 100 purchasers is selected and each person is aske
> Occasionally, warning flares of the type contained in most automobile emergency kits fail to ignite. A consumer group wants to investigate a claim that the proportion of defective flares made by a particular manufacturer is higher than the advertised val
> Suppose that for a particular hypothesis test, the consequences of a Type I error are very serious. Would you want to carry out the test using a small significance level a (such as 0.01) or a larger significance level (such as 0.10)? Explain the reason f
> One type of error in a hypothesis test is rejecting the null hypothesis when it is true. What is the other type of error that might occur when a hypothesis test is carried out?
> A television station has been providing live coverage of a sensational criminal trial. The station’s program director wants to know if more than half of potential viewers prefer a return to regular daytime programming. A survey of randomly selected viewe
> A college has decided to introduce the use of plus and minus with letter grades, as long as there is convincing evidence that more than 60% of the faculty favor the change. A random sample of faculty will be selected, and the resulting data will be used
> Which of the following specify legitimate pairs of null and alternative hypotheses? a. H0: p = 0.25 Ha: p > 0.25 b. H0: p ( 0.40 Ha: p > 0.40 c. H0: p = 0.40 Ha: p ( 0.65 d. H0: p ≠ 0.50 Ha: p = 0.50 e. H0: p = 0.50 Ha: p > 0.50 f. H0: pˆ = 0.25 Ha
> Which of the following are legitimate hypotheses? a. p = 0.65 b. p ˆ = 0.90 c. p ˆ = 0.10 d. p = 0.45 e. p > 4.30
> In a hypothesis test, what does it mean to say that the null hypothesis was not rejected?
> A press release about a paper that appeared in The Journal of Youth and Adolescence (www.springer.com/ about1springer/media/springer1select?SgwiD50-11001-6 -1433942-0, august 26, 2013, retrieved may 8, 2017) was titled “Video games Do not make Vulnerable
> The article “public acceptability in the UK and the USa of nudging to reduce obesity: the example of reducing Sugar-Sweetened beverages” (PLOS One, June 8, 2016) describes a survey in which each person in a representative sample of 1082 adult Americans w
> The article “facebook Use and academic performance among college Students” (Computers in Human Behavior [2015]: 265–272) estimated that 87% percent of students at a large public university in California who are Facebook users update their status at least
> USA TODAY (March 4, 2010) described a survey of 1000 women age 22 to 35 who work full time. Each woman who participated in the survey was asked if she would be willing to give up some personal time in order to make more money. To determine if the resulti
> Explain why the statement pˆ >0.50 is not a legitimate hypothesis.
> In a hypothesis test, what does it mean to say that the null hypothesis was rejected?
> According to an article in Science Daily (“Sill no Strong evidence that adjunct treatment with hgh in iVf improves results,” sciencedaily.com, July 4, 2016, retrieved November 26, 2016), women who are having difficulty becoming pregnant sometimes use hum
> The article “poll finds most oppose return to Draft, wouldn’t encourage children to enlist” (associated press, December 18, 2005) reports that in a random sample of 1000 American adults, 430 answered “yes” to the following question: “If the military draf
> The article “facebook Use and academic performance among college Students,” Computers in Human Behavior [2015]: 265–272) estimated that 70% of students at a large public university in California who are Facebook users log into their Facebook profiles at
> careerbuilder.com conducted a survey to learn about the proportion of employers who perform background checks when evaluating a candidate for employment (“majority of employers background check employees...here's why,” november 17, 2016, retrieved novemb
> Explain why the statement p ˆ = 0.40 is not a legitimate hypothesis.
> Past experience is that when individuals are approached with a request to fill out and return a particular questionnaire in a provided stamped and addressed envelope, the response rate is 40%. An investigator believes that if the person distributing the
> Public Policy Polling conducts an annual poll on sportsrelated issues. In 2015, they found that in a sample of 1222 adult Americans, 794 said that they thought the designated hitter rule in professional baseball should be eliminated and that pitchers sho
> Suppose that the sample of 899 college students described in the previous exercise can be regarded as representative of college students in the United States. a. What hypotheses would you test to answer the question posed in the previous exercise? b. I
> The paper “i Smoke but i am not a Smoker” (Journal of American College Health [2010]: 117–125) describes a survey of 899 college students who were asked about their smoking behavior. Of the students s
> Refer to the instructions prior to this exercise. The article “the average american is in credit card Debt, no matter the economy” (Money, february 9, 2016) states that in 2015, the average credit card debt for America
> “most Like it hot” is the title of a press release issued by the Pew Research Center (march 18, 2009, www.pewsocialtrends. org). The press release states that “by an overwhelming margin, Americans want to live in a sunny place.” This statement is based o
> The article “cops get Screened for Digital Dirt” (USA TODAY, November 12, 2010) summarizes a report on law enforcement agency use of social media to screen applicants for employment. The report was based on a survey of 728 law enforcement agencies. One q
> Suppose that you are an inspector for the Fish and Game Department and that you are given the task of determining whether to prohibit fishing along part of the Oregon coast. You will close an area to fishing if it is determined that more than 3% of fish
> The paper “Living near nuclear power plants and thyroid cancer risks” (Environmental International [2016]: 42–48) investigated whether living near a nuclear power plant increases the risk of thyroid cancer. The authors of this paper concluded that there
> Researchers at the University of Washington and Harvard University analyzed records of breast cancer screening and diagnostic evaluations (“mammogram cancer Scares more frequent than thought,” USA TODAY, April 16, 1998). Discussing the benefits and downs
> Explain why failing to reject the null hypothesis in a hypothesis test does not mean there is convincing evidence that the null hypothesis is true.
> The article “how to block nuisance calls” (The Guardian, November 7, 2015) reported that in a survey of mobile phone users, 70% of those surveyed said they had received at least one nuisance call to their mobile phone in the last month. Suppose that this
> The report "Digital Democracy Survey” (Deloitte Development LLc, 2016, www2.deloitte.com/us/en.html, retrieved November 30, 2016) says that 69% of U.S. teens age 14 to 18 years access social media from a mobile phone. Suppose you plan to select a random
> A county commissioner must vote on a resolution that would commit substantial resources to the construction of a sewer in an outlying residential area. Her fiscal decisions have been criticized in the past, so she decides to take a survey of residents in
> At one point during the 2015 NFL season, Head Coach Bill Belichick and the New England Patriots had won 19 of their past 25 called coin flips at the beginning of NFL games (“for bill belichick, patriots’ strategy is no flip of the coin,” www.bostonglobe.
> Recall that in Exercise 10.63, a survey of 304 U.S. businesses found that 201 indicated that they monitor employees’ website visits. This data was used to determine if there is convincing evidence that a majority of businesses monitor e
> Data from a large study carried out in 2008 was used to estimate that 10% of all smokers who quit smoking are smoking again after one year (“relapse to Smoking after 1 Year of abstinence: a meta-analysis,” www.ncbi.nlm
> A sample of dogs were trained using a “Do as I do” method, in which the dog observes the trainer performing a simple task (such as climbing onto a chair or touching a chair) and is expected to perform the same task on the command “Do it!” In a separate t
> A study of treatment of hospitalized patients who develop pneumonia reported that 1 in 5 (20%) are readmitted to the hospital within 30 days after discharge (“comparison of therapist-Directed and physician-Directed respiratory care in c
> We are only beginning to learn about the longterm effects of space travel on human health. A study published in 2016 (Nature Scientific Reports 6, article number: 29901, www.nature.com/articles/srep29901, July 28, 2016, retrieved may 6, 2017) found that
> The article titled “13% of Americans Don’t Use the internet. who are they?” describes a study conducted by the pew research center (pewrearch.org, September 7, 2016, retrieved December 1, 2016). Suppose that the title of this article is based on a repres
> The survey described in the previous exercise also noted that of the 965 people that had checked their credit report within the last 12 months, 38% had done so as part of their regular financial planning. Does this provide convincing evidence that more t
> A number of initiatives on the topic of legalized gambling have appeared on state ballots. A political candidate has decided to support legalization of casino gambling if he is convinced that more than two-thirds of American adults approve of casino gamb
> The article “facebook Use and academic performance among college Students” (Computers in Human Behavior [2015]: 265–272) estimated that 87% percent of students at a large public university in California who are Facebook users update their status at least
> In a representative sample of adult Americans ages 26 to 32 years, 27% indicated that they owned a fitness band that kept track of the number of steps walked each day and their daily activity levels (“Digital Democracy Survey”, Deloitte Development LLc,
> According to a large national survey conducted by the Pew Research Center (“what americans think about nSa Surveillance, national Security and privacy,” may 2, 2015, www.pewresearch.org, retrieved December 1, 2016), 54% of adult Americans disapprove of t
> In a survey of 1000 women age 22 to 35 who work full-time, 540 indicated that they would be willing to give up some personal time in order to make more money (USA TODAY, march 4, 2010). The sample was selected to be representative of women in the targete
> In a survey conducted by CareerBuilder.com, employers were asked if they had ever fired an employee for holiday shopping online while at work (“cyber Monday Shopping at work? You’re not alone,” November 22, 2016, retrieved November 30, 2016). Of the 2379
> The report “a crisis in civic education” (American council of trustees and alumni, January 2016 www.goacta.org /images/download/a_crisis_in_civic_education.pdf, retrieved November 30, 2016) summarizes data from a survey of a representative sample of 100
> Duck hunting in populated areas faces opposition on the basis of safety and environmental issues. In a survey to assess public opinion regarding duck hunting on Morro Bay (located along the central coast of California), a random sample of 750 local resid
> The report “2007 electronic monitoring and Surveillance Survey: many companies monitoring, recording, Videotaping—and firing—employees” (american management association, 2007) summarized a survey of 304 U.S. businesses. Of these companies, 201 indicated
> A representative sample of 1000 likely voters in the United States included 440 who indicated that they think that women should not be required to register for the military draft (“most women oppose having to register for the Draft,” www .rasmessenreport
> Assuming a random sample from a large population, for which of the following null hypotheses and sample sizes is the large-sample z test appropriate? a. H0: p = 0.8, n = 40 b. H0: p = 0.4, n = 100 c. H0: p = 0.1, n = 50 d. H0: p = 0.05, n = 750
> Let p denote the proportion of students living on campus at a large university who plan to move off campus in the next academic year. For a large sample z test of H0: p = 0.70 versus Ha: p > 0.70, find the P-value associated with each of the following va
> Refer to the instructions given prior to Exercise 10.57. The paper referenced in the previous exercise also reported that when each of the 1178 students who participated in the study was asked if he or she played video games at least once a day, 271 resp
> The paper “pathological Video-game Use among Youth ages 8 to 18: a national Study” (Psychological Science [2009]: 594–601) summarizes data from a random sample of 1178 students age 8 to 18. The paper
> Refer to the instructions given prior to this exercise. The paper “college Students’ Social networking experiences on facebook” (Journal of Applied Developmental Psychology [2009]: 227â€
> In a survey of 1005 adult Americans, 46% indicated that they were somewhat interested or very interested in having web access in their cars (USA TODAY, may 1, 2009). Suppose that the marketing manager of a car manufacturer claims that the 46% is based on
> The report “Digital Democracy Survey” (Deloitte Development LLc, 2016, www2.deloitte.com/us/en.html, retrieved November 30, 2016) describes a large national survey. In a representative sample of Americans ages 14 to 18 years, 45% indicated that they usua
> The article “Streaming overtakes Live tV among consumer Viewing preferences” (Variety, april 22, 2015) states that “U.S. consumers are more inclined to stream entertainment from an internet service than tune in to live TV.” This statement is based on a s
> The paper “teens and Distracted Driving” (pew internet & american Life project, 2009) reported that in a representative sample of 283 American teens age 16 to 17, there were 74 who indicated that they had sent a text message while driving. For purposes o
> The paper “Debt Literacy, financial experiences and over-indebtedness” (Social Science Research Network, working paper w14808, 2008) included data from a survey of 1000 Americans. One question on the survey was: “You owe $3000 on your credit card. You pa
> Let p denote the proportion of students at a large university who plan to purchase a campus meal plan in the next academic year. For a large-sample z test of H0: p = 0.20 versus Ha: p(0.20, find the P-value associated with each of the following values of
> Assuming a random sample from a large population, for which of the following null hypotheses and sample sizes is the large-sample z test appropriate? a. H0: p = 0.2, n = 25 b. H0: p = 0.6, n = 200 c. H0: p = 0.9, n = 100 d. H0: p = 0.05, n = 75
> USA TODAY (february 17, 2011) reported that 10% of 1008 American adults surveyed about their use of e-mail said that they had ended a relationship by e-mail. You would like to use this information to estimate the proportion of all adult Americans who hav
> The article “iphone can be addicting, Says new Survey” (www.msnbc.com, march 8, 2010) described a survey administered to 200 college students who owned an iPhone. One of the questions on the survey asked students if th
> Researchers carried out an experiment to evaluate the effectiveness of using acupuncture to treat heel pain. The experiment is described in the paper “effectiveness of trigger point Dry needling for plantar heel pain: a randomized controlled trial” (Phys
> Many fundraisers ask for donations using e-mail and text messages. The paper “now or never! the effect of Deadlines on charitable giving: evidence from two natural field experiments” (Journal of Behavioral and Experimental Economics [2016]: 1–10) describ
> In a test of hypotheses about a difference in treatment proportions, what does it mean when the null hypothesis is not rejected?
> The report “Audience Insights: Communicating to Teens (Aged 12–17)” (2009, www.cdc.gov) described teens’ attitudes about traditional media, such as TV, movies, and newspapers. In a representative sample of American teenage girls, 41% said newspapers were
> The report titled “Digital Democracy Survey” (2016, www .deloitte.com/us/tmttrends, retrieved December 16, 2016) stated that 31% of the people in a representative sample of adult Americans age 33 to 49 rated a landline telephone among the three most impo
> The news release referenced in the previous exercise also included data from independent samples of teenage drivers and parents of teenage drivers. In response to a question asking if they approved of laws banning the use of cell phones and texting while
> The Insurance Institute for Highway Safety issued a news release titled “Teen Drivers Often Ignoring Bans on Using Cell Phones” (June 9, 2008). The following quote is from the news release: Just 1–2 months prior to the ban’s Dec. 1, 2006, start, 11% of t
> The article “americans Say no to electric cars Despite gas prices” (USA TODAY, may 25, 2011) describes a survey of public opinion on issues related to rising gas prices. The survey was conducted by Gallup, a national p
> As part of a study described in the report “i can’t get my work Done!” (harmon.ie/blog/i-cant-get-my-work -done-how-collaboration-social-tools-drain-productivity, 2011, retrieved may 6, 2017), people
> A report in USA TODAY described an experiment to explore the accuracy of wearable devices designed to measure heart rate (“wearable health monitors not always reliable, study shows,” USA TODAY, october 12, 2016). The researchers found that when 50 volunt
> Example 11.1 describes a study in which 354 of 708 people in the sample of 18- to 29-year-olds and 412 of the 1029 people in the sample of 30- to 49-year-olds said that they thought it was OK to use a cell phone in a restaurant. Note that the sample size
> 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