For the numerical variables in the previous exercise, which are discrete and which are continuous?
> The graphical display at the top left of the next page is similar to one that appeared in USA TODAY (October 22, 2009). It summarizes survey responses to a question about visiting social networking sites while at work. Which of the graph types introduced
> The article “the wedding industry’s Pricey little Secret” (June 12, 2013, www.slate.com, retrieved april 19, 2017) stated that the widely reported average wedding cost is grossly misleading. The article reports that in 2012, the average wedding cost was
> The accompanying comparative segmented bar charts are similar to ones appearing in the report “The Future of the First Amendment: 2014 Survey of High School Students and Teachers” (www.knightfoundation .org/future-firs
> The Center for Science in the Public Interest evaluated school cafeterias in 20 school districts across the United States. Each district was assigned a numerical score on the basis of rigor of food codes, frequency of food safety inspections, access to i
> The following display is similar to one that appeared in USA TODAY (June 29, 2009). It is meant to be a bar graph of responses to the question shown in the display. a. Is response to the question a categorical or numerical variable? b. Explain why a ba
> One cause of tennis elbow, a malady that strikes fear into the hearts of all serious tennis players, is the impact induced vibration of the racket-and-arm system at ball contact. The likelihood of getting tennis elbow depends on various properties of the
> The National Center for Education Statistics included the following data on the average cost per year for tuition, fees, and room and board for four-year public institutions in the United States (nces.ed.gov/fastfacts/display.asp?id=76, retrieved April 1
> Consumer Reports (www.consumerreports.org) rated 37 different models of laptops that were for sale in 2015. An overall score was assigned to each model based on considering a number of factors, including performance, portability, and battery life. Data o
> The Census Bureau collects data on the percentage of households in the United States that have a computer. The accompanying table shows this percentage for the years 1984 to 2013 (census.gov/hhes/computer/publications/2012.html, retrieved August 1, 2016)
> The report “Credit Card & Debit Card Fraud Statistics” (www.cardhub.com/edu/credit-debit-card-fraud-statistics/, retrieved April 17, 2017) included the data in the accompanying table on the amount of money lost to
> The Census Bureau collects data on the percentage of households in the United States that have Internet access in the home. The accompanying table shows this percentage for the years 1997 to 2013 (census.gov/hhes/computer /publications/2012.html, retriev
> The accompanying table provides data on a measure of emotional health and a measure of the quality of the work environment for 12 different occupations. These data are from an article titled “U.S. Teachers Love Their Lives, but Struggle
> Data on weekday exercise time for 20 females, consistent with summary quantities given in the paper “an ecological Momentary assessment of the Physical activity and Sedentary behaviour Patterns of university Students”
> The report “Daily Cigarette Use: Indicators on Children and Youth” (Child Trends Data Bank, www .childtrends.org/wp-content/uploads/2012/11/03_Smoking _new.pdf, retrieved April 17, 2017) included the accompanying data
> Consumer Reports Health (www.consumerreports.org) gave the following data on saturated fat (in grams), sodium (in mg), and calories for 36 fast-food items. a. Construct a scatterplot using y 5 calories and x 5 fat. Does it look like there is a relations
> The accompanying data are the percentage of drivers who are uninsured in each of the 50 U.S. states and the District of Columbia (DC) as reported in the article “2015’s Most and Least Risky States for Driversâ
> The accompanying frequency distribution summarizes data on the number of times smokers attempted to quit before their final successful attempt (“Demographic Variables, Smoking Variables, and Outcome Across Five Studies,â€
> The accompanying data on annual maximum wind speed (in meters per second) in Hong Kong for each year in a 45-year period are from an article that appeared in the journal Renewable Energy (March 2007). Use the data to construct a histogram. Is the histogr
> The Bloomberg Visual Data web site included the following data on the total number of federal firearm background checks performed in 2014 and also the number of background checks per 1000 residents in 2014 for each of the 50 U.S. states (www.bloomberg.co
> The paper “Simpson’s Paradox: A Data and Discrimination Case Study Exercise” (Journal of Statistics Education [2014]) included data on the ages (in years) of clients of the California Department of De
> Example 2.9 provided data on seat belt use for each of the 50 U.S. states and the District of Columbia (“Traffic Safety Facts,” June, 2015, National Highway Traffic Safety Administration). The same report also gave dat
> Using the five class intervals 100 to ( 120, 120 to (140,…, 180 to , 200, construct a frequency distribution based on 70 observations whose histogram could be described as follows: a. symmetric b. bimodal c. positively skewed d. negatively skewed
> The accompanying relative frequency table is based on data from the 2015 College Bound Seniors report for California (College Board, 2016). a. Construct a relative frequency histogram for males. b. Using the same scale as the histogram from Part (a), c
> Data on weekday exercise time for 20 males, consistent with summary quantities given in the paper “an ecological Momentary assessment of the Physical activity and Sedentary behaviour Patterns of university Students” (H
> Wikipedia gives the following data on percentage increase in population between 2010 and 2015 for the 50 U.S. states and the District of Columbia (DC) (en.wikipedia.org /wiki/List_of_U.S._states_by_population_growth_rate, retrieved October 16, 2016). Eac
> Credit card fraud is a growing problem for both consumers and merchants. The data below on the percentage of credit card holders who have been impacted by fraud between 2009 and 2014 for 20 countries appeared in the article “Credit Card
> The report “Seat Belt Use in 2014” (National Highway Traffic Safety Administration) included the estimated percentages of drivers who wear seat belts for the 50 states and the District of Columbia. In the accompanying
> The following data on violent crime on Florida college campuses during 2014 are from the FBI web site. a. Construct adotplot using the 15 observations on number of violent crimes reported. Which schools stand out from the rest? b. One of the Florida sc
> An exam is given to students in an introductory statistics course. Comment on the expected shape of the histogram of scores if: a. the exam is very easy b. the exam is very difficult c. half the students in the class have had calculus, the other half
> The following two relative frequency distributions were constructed from data in the report “Undergraduate Students and Credit Cards in 2004” (Nellie Mae, May 2005). One distribution summarizes credit bureau data for a
> A report from Texas Transportation Institute (Texas A&M University System, 2005) titled “Congestion Reduction Strategies” included the following data on extra travel time during rush hour for very large and for lar
> USA TODAY (June 11, 2010) gave the following data on median age for each of the 50 U.S. states and the District of Columbia (DC). Construct a stem-and-leaf display using stems 28, 29,…,42. Comment on shape, center, and variability of
> Box Office Mojo (www.boxofficemojo.com) tracks movie ticket sales. Ticket sales (in millions of dollars) for each of the top 20 movies in 2014 and 2015 are shown in the accompanying tables. Continue to next pages… Construct com
> An article in the San Luis Obispo New Times (February 4, 2016) reported the accompanying concussion rates for different high school sports. The given data are concussion rates per 10,000 athletes participating in high school sports in 2012. a. Construct
> The 2015 urban Mobility Scorecard (texas a&M transportation institute, mobility.tamu.edu/ums/report/, rerieved april 19, 2017) included data on the estimated cost (in millions of dollars) resulting from traffic congestion for different urban areas. T
> In the United States, movies are rated by the Motion Picture Association of America (MPAA). The accompanying table gives the MPAA rating of the 25 top moneymaking movies of 2015 (data from www.boxofficemojo .com, retrieved October 10, 2016). Use the give
> The report “2013 International Bedroom Poll: Summary of Findings” describes a survey of 251 adult Americans conducted by the National Sleep Foundation (www.sleep foundation.org/sites/default/files/RPT495a.pdf, retrieved April 15, 2017). Participants in t
> The report “Findings from the 2014 College Senior Survey” (Higher Education Research Institute, December 2014) summarizes data collected from more than 13,000 college seniors across the United States. One question in t
> Heal the Bay is an environmental organization that releases an annual beach report card based on water quality (Heal the Bay Beach Report Card, www.beachreportcard.org, retrieved May 7, 2016). The grades for 20 beaches in three counties in Washington (Wh
> Each year, The Princeton Review conducts surveys of high school students who are applying to college and of parents of college applicants. The report “2016 College Hopes & Worries Survey Findings” (www.princetonre
> The report “Trends in Education 2010: Community Colleges” (www.collegeboard.com/trends) included the accompanying information on student debt for students graduating with an AA degree from a public community college in
> The report referenced in the previous exercise also gave responses to the question “What do you think is the best long-term investment?” by gender. Relative frequencies for the six response categories for men and for w
> The Gallup report “More Americans Say Real Estate Is Best Long-Term Investment” (www.gallup.com, April 20, 2016, retrieved April 15, 2017) included data from a poll of 1015 adults. The responses to the question â
> To learn about TV viewing habits of high school students, each person in a sample of students was asked how many hours he or she spent watching TV during the previous week. Required: 1. How many variables are in the data set? 2. Are the variables in th
> To learn if there is a relationship between water consumption and headache frequency, people in a sample of young adults were asked how much water (in ounces) they drink in a typical day and how many days per month they experience a headache. Required:
> The insurance institute for highway Safety (www.iihs .org, June 11, 2009) published data on repair costs for cars involved in different types of accidents. In one study, seven different 2009 models of mini- and micro-cars were driven at 6 mph straight in
> To compare the number of hours spent studying in a typical week for male and female students, data were collected from each person in a random sample of 50 female students and each person in a random sample of 50 male students. Required: 1. How many var
> To learn about what super power middle school students would most like to have, each person in a sample of middle school students was asked to choose among invisibility, extreme strength, the ability to freeze time, and the ability to fly. Required: 1.
> Classify each of the following variables as either categorical or numerical. a. Number of text messages sent by a college student in a typical day b. Amount of time a high school senior spends playing computer or video games in a typical day c. Number
> Classify each of the following variables as either categorical or numerical. a. Color of an M&M candy selected at random from a bag of M&M’s b. N umber of green M&M’s in a bag of M&M’s c. Weight (in grams) of a bag of M&M’s d. G ender of the next per
> For the numerical variables in the previous exercise, which are discrete and which are continuous?
> Classify each of the following variables as either categorical or numerical. a. W eight (in ounces) of a bag of potato chips b. Number of items purchased by a grocery store customer c. Brand of cola purchased by a convenience store customer d. A moun
> To learn about political affiliation (Democrat, Republican, Independent, and Other) of students at a particular college, each student in a random sample of 200 students was asked to indicate his or her political affiliation. Required: 1. How many variab
> To learn how the amount of money spent on a fast-food meal might differ for men and women, the amount spent on lunch at a particular fast-food restaurant was determined for each person in a sample of 50 women and each person in a sample of 50 men. Requi
> To learn how GPA at the end of the freshman year in college is related to high school GPA, both high school GPA and freshman year GPA were determined for each student in a sample of 100 students who had just completed their freshman year at a particular
> Data on tipping percent for 20 restaurant tables, consistent with summary statistics given in the paper “racial and ethnic Differences in tipping: the role of Perceived Descriptive and injunctive tipping norms” (Restau
> To see if there is a difference in car color preferences of men and women, each person in a sample of 100 males and each person in a sample of 100 females was shown pictures of a new model car in five different colors and asked to select which color they
> To learn about the heights of five-year-old children, the height of each child in a sample of 40 five-year-old children was measured. Required: 1. How many variables are in the data set? 2. Are the variables in the data set categorical or numerical? 3
> For the following numerical variables, state whether each is discrete or continuous. a. The length of a 1-year-old rattlesnake b. The altitude of a location in California selected randomly by throwing a dart at a map of the state c. The distance from
> Classify each of the following variables as either categorical or numerical. For those that are numerical, determine whether they are discrete or continuous. a. Brand of computer purchased by a customer b. State of birth for someone born in the United
> To learn about how much money students at a particular college spend on textbooks, each student in a random sample of 200 students was asked how much he or she spent on textbooks for the current semester.
> To see if there is a difference between faculty and students at a particular college with respect to how they commute to campus (drive, walk, bike, and so on), each person in a random sample of 50 faculty members and each person in a random sample of 100
> To learn about how number of years of education and income are related, each person in a random sample of 500 residents of a particular city was asked how many years of education he or she had completed and what his or her annual income was. Required: 1
> To compare commute distances for full-time and part-time students at a large college, commute distance (in miles) was determined for each student in a random sample of 50 full-time students and for each student in a random sample of 50 part-time students
> The accompanying data on x = Average energy density (calories per 100 grams) and y = Average cost (in dollars) for eight different food groups are from the paper “the Cost of U.S. Foods as related to their nutritional valueâ€
> The article “$115K! the 13 best Paying U.s. Companies” (USA TODAY, august 11, 2015) gave the following data on median worker pay (in thousands of dollars) and the 1-year percent change in stock price for the 13 highest
> the accompanying data on total amount of time per day (in minutes) spent using a cell phone are consistent with summary statistics in the paper “the relationship between cell Phone use and academic Performance in a Sample of u.S. colleg
> Can you tell how old a lobster is by its size? This question was investigated by the authors of a paper that appeared in the Biological Bulletin (august 2007). Researchers measured carapace (the exterior shell) length of 27 laboratory-raised lobsters of
> The following table gives the number of heart transplants performed in the United States each year from 2006 to 2015 (U.s. Department of health and human services, optn.transplant.hrsa.gov/data/view-data-reports/national -data/, retrieved april 22, 2017
> Does it pay to stay in school? The report Trends in Higher Education (the College board, 2010) looked at the median hourly wage gain per additional year of schooling. The report states that workers with a high school diploma had a median hourly wage that
> The following data on sale price, size, and land-to-building ratio for 10 large industrial properties appeared in the paper “Using Multiple regression analysis in real estate appraisal” (Appraisal Journal [2002]: 424&a
> Is living in a large high-rise apartment building a disadvantage in a medical emergency? This question was investigated in the paper “impact of building height and volume on Cardiac arrest response time” (Prehospital E
> Explain why it can be misleading to use the least squares regression line to obtain predictions for x values that are substantially larger or smaller than the x values in the data set.
> For a given data set, the sum of squared deviations from the line y = 40 + 6x is 529.5. For this same data set, which of the following could be the sum of squared deviations from the least squares regression line? Explain your choice. i. 308.6 ii. 529
> The relationship between hospital patient-to-nurse ratio and various characteristics of job satisfaction and patient care has been the focus of a number of research studies. Suppose x = Patient-to-nurse ratio is the predictor variable. For each of the fo
> The article “air Pollution and Medical Care Use by older americans” (Health Affairs [2002]: 207– 214) gave data on a measure of pollution (in micrograms of particulate matter per cubic meter of air) a
> Based on data from six countries, the paper “a Crossnational relationship between sugar Consumption and Major Depression?” (Depression and Anxiety [2002]: 118–120) concluded that there was a correlati
> The paper “can Pizza Fit in to the renal Diet? a review of the Phosphorus, Potassium and Sodium content of Selected Frozen and Delivery options” (Journal of Renal Nutrition [2015]: e15–e18) gave infor
> The accompanying data are x = Cost (cents per serving) and y = Fiber content (grams per serving) for 18 high-fiber cereals rated by Consumer Reports (www.consumerreports.org /health). a. Construct a scatterplot of y 5 Fiber content versus Cost. Based o
> 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) studied the relationship between y = Arch heigh
> For each of the following pairs of variables, indicate whether you would expect a positive correlation, a negative correlation, or a correlation close to 0. Explain your choice. a. Price and weight of an apple b. A person’s height and the number of pet
> For each of the four scatterplots shown, answer the following questions: i. Does there appear to be a relationship between x and y? ii. If so, does the relationship appear to be linear? iii. If so, would you describe the linear relationship as positiv
> The following quote is from the paper “the weight of the bottle as a Possible extrinsic Cue with which to estimate the Price (and Quality) of the wine? observed Correlations” (Food Quality and Preference [2012]: 41–45): The weight of the wine bottles was
> The paper “Depression, body Mass index, and Chronic obstructive Pulmonary Disease—a holistic approach” (International Journal of COPD [2016]:239– 249) gave data on change in Body Mas
> The California state Park system statistical report for the 2014/2015 Fiscal Year (www.parks.ca.gov/pages/795/files/14-15%20statistical%20report%20-%20internet .pdf, retrieved April 22, 2017) gave the accompanying data on x 5 Amount of money collected in
> The paper “effects of age and gender on Physical Performance” (Age [2007]: 77–85) describes a study investigating the relationship between age and swimming performance. Data on age and 1-hour swim dis
> The article “examined life: what stanley h. Kaplan taught Us about the sat” (The New Yorker [December 17, 2001]: 86–92) included a summary of findings regarding the use of SAT I scores, SAT II scores, and high school grade point average (GPA) to predict
> The first Batman movie was made over 50 years ago in 1966. Over the years, Batman has been played on screen by a number of actors and even by a Lego figure in the Lego Batman movies. In the original comic books, Batman was described as being 188 cm tall
> The report titled “State of the news Media 2013” (Pew research center, May 7, 2013) included the weekday circulation numbers for the top 20 newspapers in the country. Here are the data for the 6 months ending September
> The article “Master’s Performance in the New York City Marathon” (British Journal of Sports Medicine [2004]: 408–412) gave the following data on the average finishing time (in minute
> The report “airline Quality rating 2016” (airlinequalityrating.com/reports/2016_aQr_Final.pdf, retrieved April 22, 2017) included the data for 13 U.S. airlines given in the table below. a. With x = Airline quality r
> Briefly explain why it is important to consider the value of se in addition to the value of r2 when evaluating the usefulness of the least squares regression line.
> Briefly explain why a large value of r2 is desirable in a regression setting.
> Some types of algae have the potential to cause damage to river ecosystems. The accompanying data on y = Algae colony density and x = Rock surface area for nine rivers are a subset of data that appeared in a scatterplot in a paper in the journal Aquatic
> Researchers have observed that bears hunting salmon in a creek often carry the salmon away from the creek before eating it. The relationship between x 5 Total number of salmon in a creek and y 5 Percentage of salmon killed by bears that were transported
> Acrylamide is a chemical that is sometimes found in cooked starchy foods and which is thought to increase the risk of certain kinds of cancer. The paper “a statistical regression Model for the estimation of acrylamide Concentrations in
> The paper referenced in the previous exercise also gave the 6-minute walk distances for 248 girls ages 3 to 18 years. The median distances for the five age groups were 492.4 578.3 655.8 657.6 660.9 a. With x = Representative age and y = Median
> The data in the accompanying table are from the paper “six-Minute walk test in Children and adolescents” (The Journal of Pediatrics [2007]: 395–399). Two hundred and eighty boys completed a test that
> Briefly explain why it is important to consider the value of r2 in addition to the value of se when evaluating the usefulness of the least squares regression line.
> For the data of Exercise 3.22, multiply each data value by 10, then calculate the standard deviation. How does this value compare to s for the original data? More generally, what happens to s if each observation is multiplied by the same positive constan
