Question: A random sample will be selected from

> In a study of high-achieving high school graduates, the authors of the report “High-Achieving Seniors and the College Decision” (Lipman Hearne, October 2009) surveyed 828 high school graduates who were considered &acir

> The report referenced in the previous two exercises also classified 817 fatal bicycle accidents according to the month in which the accidents occurred, resulting in the accompanying table. a. To determine if some months are riskier than others, use the

> Suppose a safety officer proposes that bicycle fatalities are twice as likely to occur between noon and midnight as during midnight to noon and suggests the following hypothesis: /where p1 is the proportion of accidents occurring between midnight and noo

> The report “Fatality Facts 2004: Bicyclists 2015” (Insurance Institute, 2015, www.iihs.org/iihs/topics/t/pedestrians-and-bicyclists/fatalityfacts/bicycles, retrieved May 27, 2017) included the following table classifyi

> The authors of the paper “Racial Stereotypes in Children’s Television Commercials” ( Journal of Advertising Research [2008]: 80–93) counted the number of times that characters of dif

> Jail inmates can be classified into one of the following four categories according to the type of crime committed: violent crime, crime against property, drug crime, and public-order offenses. Suppose that random samples of 500 male inmates and 500 femal

> The authors of the paper “Risk of Malnutrition Is an Independent Predictor of Mortality, Length of Hospital Stay, and Hospitalization Costs in Stroke Patients” (Journal of Stroke and Cerebrovascular Diseases [2016]: 79

> The report referenced in the previous exercise also provided data on perception of money management skills by age group. Use the data from 788 people in the accompanying table to determine if there is evidence of an association between age and perception

> The report “Majoring in Money: How American College Students Manage Their Finances” (June 28, 2016, salliemae.newshq.businesswire.com/sites/salliemae.newshq.businesswire .com/files/doc_library/file/SallieMae_Majoringin

> Does viewing angle affect a person’s ability to tell the difference between a female nose and a male nose? This important (?) research question was examined in the article “You Can Tell by the Nose: Judging Sex from an

> Each person in a representative sample of 445 college students age 18 to 24 was classified according to age and to the response to the following question: “How often have you used a credit card to buy items knowing you wouldnâ&#12

> The report “Smartphone Ownership and Internet Usage Continues to Climb in Emerging Economies” (Pew Research Center, February 22, 2016, www.pewglobal .org/2016/02/22/smartphone-ownership-and-internet -usage-continues-to

> Are babies born to mothers who use assistive reproduction technology (ART) more likely to be born prematurely than babies conceived naturally? The data in the accompanying table are from the paper “Child Growth from Birth to 18 Months A

> Explain the difference between situations that would lead to a chi-square test for homogeneity and those that would lead to a chi-square test for independence.

> Explain the difference between situations that would lead to a chi-square goodness-of-fit test and those that would lead to a chi-square test of homogeneity.

> Give an example of a situation where it would be appropriate to use a chi-square test of independence. Describe the population that would be sampled and the two variables that would be recorded.

> Give an example of a situation where it would be appropriate to use a chi-square test of homogeneity. Describe the populations that would be sampled and the variable that would be recorded.

> Each person in a large sample of German adolescents was asked to indicate which of 50 popular movies he or she had seen in the past year. Based on the response, the amount of time (in minutes) of alcohol use contained in the movies the person had watched

> The paper “Contemporary College Students and Body Piercing” (Journal of Adolescent Health [2004]: 58–61) described a survey of 490 undergraduate students at a state university in the southwestern regi

> The Knight Foundation investigated whether high school students agreed with the statement that people should be allowed to burn or deface the American flag as a political statement. This question was asked in a survey of a representative sample of high s

> The data in the accompanying table are from the paper “Gender Differences in Food Selections of Students at a Historically Black College and University” (College Student Journal [2009]: 800–806). Supp

> The paper “Credit Card Misuse, Money Attitudes, and Compulsive Buying Behavior: Comparison of Internal and External Locus of Control Consumers” (College Student Journal [2009]: 268–275) describes a su

> The authors of the paper “The Relationship of Field of Study to Current Smoking Status Among College Students” (College Student Journal [2009]: 744–754) carried out a study to investigate if smoking r

> The Knight Foundation asked each person in a representative sample of high school students and in a representative sample of high school teachers which of the rights guaranteed by the First Amendment they thought was the most important (â€&#15

> Some colleges now allow students to pay their tuition using a credit card. The report “Credit Card Tuition Payment Survey 2014” (www.creditcards.com/credit-card -news/tuition-charge-fee-survey.php, retrieved May 27, 20

> The authors of the paper “External Factors and the Incidence of Severe Trauma: Time, Date, Season and Moon” (Injury [2014]: S93–S99) classified admissions to hospitals in Germany according to season.

> Birds use color to select and avoid certain types of food. The authors of the article “Colour Avoidance in Northern Bobwhites: Effects of Age, Sex, and Previous Experience” (Animal Behaviour [1995]: 519â€&#1

> Suppose that each observation in a random sample of 100 fatal bicycle accidents in 2015 was classified according to the day of the week on which the accident occurred. Data consistent with information on the Insurance Institute for Highway Safety website

> The article “Linkage Studies of the Tomato” (Transactions of the Royal Canadian Institute [1931]: 1–19) reported the accompanying data on phenotypes resulting from crossing tall cut-leaf tomatoes with

> A certain genetic characteristic of a particular plant can appear in one of three forms (phenotypes). A researcher has developed a theory, according to which the hypothesized proportions are p1 = 0.25, p2 = 0.50, and p3 = 0.25. A random sample of 200 pla

> Think about how you would answer the following question. Next Wednesday’s meeting has been moved forward two days. What day is the meeting now that it has been rescheduled? This question is ambiguous, as “moved forwa

> For which of the X 2 and df pairs in the previous exercise would the null hypothesis be rejected if a significance level of  = 0.01 were used?

> What is the approximate P-value for the following values of X 2 and df? a. X 2 = 34.52, df = 13 b. X 2 = 39.25, df = 16 c. X 2 = 26.00, df = 19

> A popular urban legend is that more babies than usual are born during certain phases of the lunar cycle, especially near the full moon. The paper “The Effect of the Gravitation of the Moon on Frequency of Births” (Envi

> The “Global Automotive 2016 Color Popularity Report” (Axalta Coating Systems, www.axaltacs.com, retrieved May 27, 2017) included data on the colors for a sample of new cars sold in North America. The report stated that 25% of the cars in the sample were

> The authors of the paper “Talking Smack: Verbal Aggression in Professional Wrestling” (Communication Studies [2008]: 242–258) analyzed the content of 36 hours of televised professional wrestling. Each

> Packages of mixed nuts made by a certain company contain four types of nuts. The percentages of nuts of Types 1, 2, 3, and 4 are advertised to be 40%, 30%, 20%, and 10%, respectively. A random sample of nuts is selected, and each one is categorized by ty

> What is the approximate P-value for the following values of X 2 and df? a. X 2 = 14.44, df = 6 b. X 2 = 16.91, df = 9 c. X 2 = 32.32, df = 20

> In 2014, the University of Houston carried out a study for the Texas Lottery Commission (“Demographic Survey of Texas Lottery Players,” www.uh.edu/class/hobby/_docs /Texas%20Lottery%20Study%202014.pdf, retrieved May 27

> The article “In Bronx, Hitting Home Runs Is a Breeze” (USA TODAY, June 2, 2009) included a classification of 87 home runs hit at the new Yankee Stadium according to the direction that the ball was hit, resulting in the

> The authors of the paper “Is It Really About Me? Message Content in Social Awareness Streams” (Computer Supported Cooperative Work 2010) studied a random sample of 350 Twitter users. For each Twitter user in the sample

> What is the approximate P-value for the following values of X 2 and df? a. X 2 = 6.62, df = 3 b. X 2 = 16.97, df = 10 c. X 2 = 30.19, df = 17

> A particular cell phone case is available in a choice of four different colors. A store sells all four colors. To test the hypothesis that sales are equally divided among the four colors, a random sample of 100 purchases is identified. a. If the resulti

> The article “an alternative Vote: applying Science to the teaching of Science” (The Economist, may 12, 2011) describes an experiment conducted at the University of British Columbia. A total of 850 engineering students enrolled in a physics course partici

> In a survey of a representative sample of adults in the United States, participants were asked if they agreed or disagreed with the statement “I can’t imagine my life without my smartphone” (july 13,

> Suppose that the actual proportion of students at a particular college who use public transportation to travel to campus is 0.15. In a study of parking needs at the campus, college administrators would like to estimate this proportion. They plan to take

> The company Digital Trends reported that 48% of Americans have shared passwords for TV and movie streaming (“americans Know they Shouldn't Share their passwords, but Do it anyway,” february 18, 2016, www.digitaltrends.com /computing/everyone-shares-passw

> The article “fewer americans are reading, but Don't blame the millennials” (Los Angeles Times, october 9, 2016) indicates that 80% of millennials (those age 18–29) have read a book in the last year. Suppose that this is the actual percentage for the popu

> For which of the sample sizes given in the previous exercise would the sampling distribution of pˆ be approximately normal if p = 0.70? If p = 0.30?

> Consider the following statement: The proportion of all students enrolled at a particular university during 2017 who lived on campus was 0.21. a. Is the number that appears in boldface in this statement a sample proportion or a population proportion? b

> Consider the following statement: An inspector selected 20 eggs at random from the eggs processed at a large egg production facility. These 20 eggs were tested for salmonella, and the proportion of the eggs that tested positive for salmonella was 0.05.

> Explain why there is sample-to-sample variability in pˆ but not in p.

> Consider the following three relative frequency histograms. Each histogram was constructed by selecting 100 random samples from a population composed of 40% women and 60% men. For each sample, the sample proportion of women, pˆ, was calculated

> A random sample of 50 registered voters in a particular city included 32 who favored using city funds for the construction of a new recreational facility. For this sample, pˆ= 32 = 0.64. If a 50 second random sample of 50 registered voters w

> The article referenced in the previous exercise also reported that 38% of the 1200 social network users surveyed said it was OK to ignore a coworker’s friend request. If pˆ = 0.38 is used as an estimate of the proportion of all social network users who b

> The article “facebook etiquette at work” (USA TODAY, march 24, 2010) reported that 56% of 1200 social network users surveyed indicated that they thought it was not OK for someone to “friend” his or her boss. Suppose that this sample can be regarded as a

> In a study of pet owners, it was reported that 24% celebrate their pet’s birthday (Pet Statistics, bissell homecare, inc., 2010). Suppose that this estimate was based on a random sample of 200 pet owners. Is it reasonable to conclude that the proportion

> Some colleges now allow students to rent textbooks for a semester. Suppose that 38% of all students enrolled at a particular college would rent textbooks if that option were available to them. If the campus bookstore uses a random sample of size 100 to e

> The report “a crisis in civic education” (january 2016, goacta.org/images/download/a_crisis_in_civic_education .pdf, retrieved may 3, 2017) indicated that in a survey of a random sample of 1000 recent college graduates, 96 indicated that they believed th

> The article “60% of employers are peeking into candidates’ Social media profiles” (careerbuilders, april 28, 2016, nscresearchcenter.org/wp-content/uploads/Snapshotreport17 -2Yearcontributions.pdf, retrieved october 9, 2016) included data from a survey o

> The article “cSi effect has juries wanting more evidence” (USA TODAY, august 5, 2004) examines how the popularity of crime-scene investigation television shows is influencing jurors’ expectations of w

> Suppose that 20% of the customers of a cable television company watch the Shopping Channel at least once a week. The cable company does not know the actual proportion of all customers who watch the Shopping Channel at least once a week and is trying to d

> The report “the role of two-Year institutions in fourYear Success” (national Student clearinghouse research center, 2015, nscresearchcenter.org/wp-content/uploads /Snapshotreport17-2Yearcontributions.pdf, retrieved may 3, 2017) states that nationwide, 46

> The article “Long-term effects of tongue piercing—a case-control Study” (Clinical Oral Investigations [2012]: 231– 237) describes a study of 46 males with pierced tongues. Suppose that it is reasonable to regard this sample as a random sample from the po

> The article “the average american is in credit card Debt, no matter the economy” (Money Magazine, february 9, 2016) reported that only 35% of credit card users pay off their bill every month. Suppose that the reported

> Suppose that a particular candidate for public office is favored by 48% of all registered voters in the district. A polling organization will take a random sample of 500 of these voters and will use pˆ, the sample proportion, to estimate p. a. Show that

> The article “facebook etiquette at work” (USA TODAY, March 24, 2010) reported that 56% of people participating in a survey of social network users said it was not OK for someone to “friend” his or her boss. Let p denote the proportion of all social netwo

> For which of the population proportions given in the previous exercise would the sampling distribution of pˆ be approximately normal if n = 40? If n = 75?

> A random sample of size 300 is to be selected from a population. Determine the mean and standard deviation of the sampling distribution of pˆ for each of the following population proportions. a. p = 0.20 b. p = 0.45 c. p = 0.70 d. p = 0.90

> For which of the following sample sizes would the sampling distribution of pˆ be approximately normal when p = 0.2? When p = 0.8? When p = 0.6? n = 10 n = 25 n = 50 n = 100

> Explain why the standard deviation of pˆ is equal to 0 when the population proportion is equal to 1.

> For which of the following combinations of sample size and population proportion would the standard deviation of pˆ be smallest? n = 40 p = 0.3 n = 60 p = 0.4 n = 100 p = 0.5

> The U.S. Census Bureau reported that in 2015 the proportion of adult Americans age 25 and older who have a bachelor’s degree or higher is 0.325 (“educational attainment in the United States: 2015,” www.census.gov, retrieved January 22, 2017). Consider th

> A certain chromosome defect occurs in only 1 in 200 adult Caucasian males. A random sample of 100 adult Caucasian males will be selected. The proportion of men in this sample who have the defect, pˆ, will be calculated. a. What are the mean and standard

> For which of the sample sizes given in the previous exercise would the sampling distribution of pˆ be approximately normal if p = 0.25? If p = 0.6?

> A random sample is to be selected from a population that has a proportion of successes p = 0.25. Determine the mean and standard deviation of the sampling distribution of pˆ for each of the following sample sizes: a. n = 10 b. n = 20 c. n = 30 d.

> The article referenced in the previous exercise also reported that for people age 18 to 29 who prefer to watch the news, the proportion that prefer to watch online is 0.37. Answer the questions posed in Parts (a)–(d) of the previous exercise for the popu

> The article “Younger adults more Likely than their elders to prefer reading the news” (October 6, 2016, www .pewresearch.org/fact-tank/2016/10/06/younger-adults -more-likely-than-their-elders-to-prefer-reading-news/) estimated that only 3% of those age 6

> For which of the sample sizes given in the previous exercise would the sampling distribution of p ˆ be approximately normal if p = 0.65? If p = 0.2?

> A random sample is to be selected from a population that has a proportion of successes p = 0.65. Determine the mean and standard deviation of the sampling distribution of pˆ for each of the following sample sizes: a. n = 10 b. n = 20 c. n = 30 d.

> Consider the following statement: A county tax assessor reported that the proportion of property owners who paid 2016 property taxes on time was 0.93. a. Is the number that appears in boldface in this statement a sample proportion or a population propor

> Consider the following statement: In a sample of 20 passengers selected from those who flew from Dallas to New York City in April 2017, the proportion who checked luggage was 0.45. a. Is the number that appears in boldface in this statement a sample pro

> Consider the two relative frequency histograms at the top of the next page. The histogram on the left was constructed by selecting 100 different random samples of size 35 from a population in which 17% donated to a nonprofit organization. For each sample

> Explain what it means when we say the value of a sample statistic varies from sample to sample.

> Consider the following statement: The proportion of all calls made to a county 9-1-1 emergency number during the year 2017 that were nonemergency calls was 0.14. a. Is the number that appears in boldface in this statement a sample proportion or a popula

> Consider the following statement: Fifty people were selected at random from those attending a football game. The proportion of these 50 who made a food or beverage purchase while at the game was 0.83. a. Is the number that appears in boldface in this st

> Explain what the term sampling variability means in the context of using a sample proportion to estimate a population proportion.

> Consider the two relative frequency histograms at the top of the next page. The histogram on the left was constructed by selecting 100 different random samples of size 40 from a population consisting of 20% part-time students and 80% full-time students.

> A random sample of 100 employees of a large company included 37 who had worked for the company for less than one year. For this sample, pˆ = 37 = 0.37. If a different 100 random sample of 100 employees were selected, would you expect that

> Explain the difference between p and pˆ.

> Consider the following statement: A sample of size 100 was selected from those admitted to a particular college in fall 2017. The proportion of these 100 who were transfer students is 0.38. a. Is the number that appears in boldface in this statement a s

> Consider the following statement: The Department of Motor Vehicles reports that the proportion of all vehicles registered in California that are imports is 0.22. a. Is the number that appears in boldface in this statement a sample proportion or a popula

> Consider the two relative frequency histograms at the bottom of this page. The histogram on the left was constructed by selecting 100 different random samples of size 50 from a population consisting of 55% females and 45% males. For each sample, the samp

> A random sample of 1000 students at a large college included 428 who had one or more credit cards. For this sample, pˆ = 428 = 0.428. If another random sample of 1000 students from 1000 this university were selected, would you expect

> The process for statistical inference described in Section 7.3 consists of five steps: a. What are the five steps in the process for estimation problems? b. Explain how the first step differs for estimation problems and hypothesis testing problems.

> The authors of the paper “flat-footedness is not a Disadvantage for athletic Performance in children aged 11 to 15 Years” (Pediatrics [2009]: e386–e392) collected data from 218 children on foot arch h

> In a study to determine if using low-intensity laser therapy reduces pain for orthodontic patients who are fitted with new braces, patients were randomly assigned to either a control group (who did not receive laser treatment) and an experimental group w

> Refer to the instructions prior to this exercise. A study of adult Americans conducted by the polling organization Ipsos (“One in Five Americans Consider Themselves ‘Entrepreneurs,’”

> Explain why the question T: Type of data—one variable or two? Categorical or numerical? is one of the four key questions used to guide decisions about what inference method should be considered.

> Suppose that a study was carried out in which each student in a random sample of students at a particular college was asked if he or she was registered to vote. Would these data be used to estimate a population mean or to estimate a population proportion