In the article “Material Culture as Memory: Combs and Cremations in Early Medieval Britain” (Early Medieval Europe, Vol. 12, Issue 2, pp. 89–128), H. Williams discussed the frequency of cremation burials found in 17 archaeological sites in eastern England. Here are the data.
a. obtain and interpret the quartiles.
b. determine and interpret the interquartile range.
c. find and interpret the five-number summary.
d. identify potential outliers, if any.
e. construct and interpret a boxplot.
> Each year, tornadoes that touch down are recorded by the Storm Prediction Center and published in Monthly Tornado Statistics. The following table gives the number of tornadoes that touched down in the United States during each month of one year. Find the
> The Tropical Cyclone Report, a publication of the National Hurricane Center, contains comprehensive information on each tropical cyclone, including synoptic history, meteorological statistics, casualties, and damages. A hurricane is a tropical cyclone wi
> In sampling, explain why obtaining a representative sample is important.
> The family of mammals called Chinchillidae contains the chinchilla and viscachas, which are large South American rodents. The article, “Species Richness and Distribution of Neotropical Rodents, with Conservation Implications” (Mammalia, Vol. 77, Issue 1,
> Explain why a sample of 30 dentists from Seattle taken to estimate the median income of all Seattle residents is not representative.
> The U.S. Census Bureau collects information about the ages of people in the United States. Results are published in Current Population Reports. a. Identify the variable and population under consideration. b. A sample of six U.S. residents yielded the fol
> 4, 2, 0, 2, 2 a. population mean. b. population standard deviation.
> 1, 9, 8, 4, 3 a. population mean. b. population standard deviation.
> 2, 5, 0, −1 a. population mean. b. population standard deviation.
> 1, 2, 4, 4 a. population mean. b. population standard deviation.
> 3, 5, 7 a. population mean. b. population standard deviation.
> 4, 0, 5 a. population mean. b. population standard deviation.
> We found that, considering the five starting players on Team II a sample of all male starting college basketball players, the mean and standard deviation of the heights are 75 inches and 6.2 inches, respectively. Explain why, numerically, the sample mean
> Explain in detail the purpose of a measure of center.
> An article by D. Schaefer et al. (Journal of Tropical Ecology, Vol. 16, pp. 189–207) reported on a long-term study of the effects of hurricanes on tropical streams of the Luquillo Experimental Forest in Puerto Rico. The study shows that Hurricane Hugo ha
> Name and describe the three most important measures of center.
> In the year 2000, an on-line poll was conducted over Memorial Day weekend that asked people what they were doing to observe the holiday. The choices were: (1) stay home and relax, (2) vacation outdoors over the weekend, or (3) visit a military cemetery.
> We analyzed the heights of the starting five players on each of two men’s college basketball teams. The heights, in inches, of the players on Team II are 67, 72, 76, 76, and 84. Regarding the five players as a population, solve the following problems. a.
> Earlier in this section, we found that the population standard deviation of the lengths of the holes at the Augusta National Golf Club is 132.0 yd. In this context, is the number 132.0 a parameter or a statistic? Explain your answer.
> Earlier in this section, we found that the population mean length of the holes at the Augusta National Golf Club is 413.1 yd. In this context, is the number 413.1 a parameter or a statistic? Explain your answer.
> Identify the statistic that is used to estimate a. a population mean. b. a population standard deviation.
> Fill in the following blanks. a. A standardized variable always has mean and standard deviation. b. The z-score corresponding to an observed value of a variable tells you. c. A positive z-score indicates that the observation is the mean, whereas a negati
> For a given brand of microwave popcorn, what property is desirable for the population standard deviation of the cooking time? Explain your answer.
> Although, in practice, sample data are generally analyzed in inferential studies, what is the ultimate objective of such studies?
> The number of patents a university receives is an indicator of the research level of the university. From a study titled Science and Engineering Indicators issued by the National Science Foundation, we found the number of U.S. patents awarded to a sample
> Identify each quantity as a parameter or a statistic. a. μ b. s c. x¯ d. σ
> Vitamin C (ascorbate) boosts the human immune system and is effective in preventing a variety of illnesses. In a study by E. Cameron and L. Pauling titled “Supplemental Ascorbate in the Supportive Treatment of Cancer: Reevaluation of Prolongation of Surv
> Advertising researchers F. Shuptrine and D. McVicker wanted to determine whether there were significant differences in the readability of magazine advertisements. Thirty magazines were classified based on their educational level high, mid, or low—and the
> The members of a population are numbered 1–50. a. Use Table I in Appendix A to obtain an SRS of size 6 from the population. Start at the two-digit number in line number 10 and column numbers 10−11, read down the column, up the next, and so on. b. If you
> In a study of the effects of radiation on amphibian embryos titled “Shedding Light on Ultraviolet Radiation and Amphibian Embryos” (BioScience, Vol. 53, No. 6, pp. 551–561), L. Licht recorded the time it took for a sample of seven different species of fr
> Anthropologists are still trying to unravel the mystery of the origins of the Etruscan empire, a highly advanced Italic civilization formed around the eighth century B.C. in central Italy. Were they native to the Italian peninsula or, as many aspects of
> L. Petersen et al. evaluated the effects of integrated treatment for patients with a first episode of psychotic illness in the paper “A Randomised Multicentre Trial of Integrated Versus Standard Treatment for Patients with a First Episode of Psychotic Il
> A study by researchers at the University of Maryland addressed the question of whether the mean body temperature of humans is 98.6◦F. The results of the study by P. Mackowiak et al. appeared in the article “A Critical Appraisal of 98.6◦F, the Upper Limit
> As reported by the U.S. Census Bureau in Educational Attainment in the United States, the percentage of adults in each state and the District of Columbia who have completed a bachelor’s degree is provided on the WeissStats site. a. obtain and interpret t
> As reported by the U.S. Census Bureau in Educational Attainment in the United States, the percentage of adults in each state and the District of Columbia who have completed high school is provided on the WeissStats site. a. obtain and interpret the quart
> R. Morris and E. Watson studied various aspects of process capability in the paper “Determining Process Capability in a Chemical Batch Process” (Quality Engineering, Vol. 10(2), pp. 389–396). In one part of the study, the researchers compared the variabi
> In the article, “Length of The Beatles’ Songs” (Chance, Vol. 25, No. 1, pp. 30–33), T. Koyama discusses aspects and interpretations of the lengths of songs by The Beatles. Data on the length, in seconds, of 229 Beatles’ songs are presented on the WeissSt
> In an article titled “Great White, Deep Trouble” (National Geographic, Vol. 197(4), pp. 2–29), Peter Benchley—the author of JAWS—discussed various aspects of the Great White Shark (Carcharodon carcharias). Data on the number of pups borne in a lifetime b
> The U.S. Department of Education sponsors a report on educational institutions, including colleges and universities, titled Digest of Education Statistics. Among many of the statistics provided are the numbers of men and women enrolled in 2-year and 4-ye
> A study published by E. Anionwu et al. in the British Medical Journal (Vol. 282, pp. 283–286) examined the steady-state hemoglobin levels of patients with three different types of sickle cell disease: HB SC, HB SS, and HB ST. Use the following boxplots t
> The members of a population are numbered 1–90. a. Use Table I in Appendix A to obtain an SRS of size 5 from the population. Start at the two-digit number in line number 15 and column numbers 25−26, read down the column, up the next, and so on. b. If you
> Many species of cuckoos are brood parasites. The females lay their eggs in the nests of smaller bird species, who then raise the young cuckoos at the expense of their own young. Data on the lengths, in millimeters (mm), of cuckoo eggs found in the nests
> Consider these sample data: x1 = 12, x2 = 8, x3 = 9, x4 = 17. a. Find n. b. Compute Σxi. c. Determine x¯.
> Researchers in obesity wanted to compare the effectiveness of dieting with exercise against dieting without exercise. Seventy-three patients were randomly divided into two groups. Group 1, composed of 37 patients, was put on a program of dieting with exe
> The National Association of Colleges and Employers (NACE) conducts surveys of salary offers to new college graduates and publishes the results in Salary Survey. The following diagram provides boxplots for the starting annual salaries, in thousands of dol
> In the paper “The Smoking Cessation Efficacy of Varying Doses of Nicotine Patch Delivery Systems 4 to 5 Years Post-Quit Day” (Preventative Medicine, 28, pp. 113–118), D. Daughton et al. discussed the long-term effectiveness of transdermal nicotine patche
> In an issue of Science (Vol. 308, No. 5721, p. 483), D. Normile reported on a study from the Japan Statistics Bureau of the 30 industrialize countries in the Organization for Economic Co-operation and Development (OECD) titled “Japan Mulls Workforce Goal
> Water parks are a huge summer attraction for vacationers in the United States. The Global Attractions Attendance Report, published by the Themed Entertainment Association, provides the attendance report for theme parks and water parks around the world. T
> In the article, “Assessing Claims Made by a Pizza Chain” by P. Dunn, (Journal of Statistics Education, Vol. 20, No. 1, pp. 1–19), a sample of pizzas from Domino’s was collected. The intention of the study was to test the claim of a local pizza shop that
> An issue of Brokerage Report discussed the capital spending of telecommunications companies in the United States and Canada. The capital spending, in thousands of dollars, for each of 27 telecommunications companies is shown in the following table. a. ob
> The publication California Wild: Natural Sciences for Thinking Animals has a monthly feature called the “Sky Guide” that keeps track of the sunrise and sunset for the first day of each month in San Francisco. Over several issues, B. Quock from the Morris
> The members of a population are numbered 1–4. a. List the 6 possible samples (without replacement) of size 2 from this population. b. If an SRS of size 2 is taken from the population, what are the chances of selecting 2 and 3? Explain your answer. c. Use
> An article by D. Schaefer et al. (Journal of Tropical Ecology, Vol. 16, pp. 189–207) reported on a long-term study of the effects of hurricanes on tropical streams of the Luquillo Experimental Forest in Puerto Rico. The study shows that Hurricane Hugo ha
> The U.S. Federal Highway Administration conducts studies on motor vehicle travel by type of vehicle. Results are published annually in Highway Statistics. A sample of 15 cars yields the following data on number of miles driven, in thousands, for last yea
> Consider these sample data: x1 = 1, x2 = 7, x3 = 4, x4 = 5, x5 = 10. a. Find n. b. Compute Σxi. c. Determine x
> The U.S. National Center for Health Statistics compiles data on the length of stay by patients in short-term hospitals and publishes its findings in Vital and Health Statistics. A random sample of 21 patients yielded the following data on length of stay,
> In the article “Sweetening Statistics—What M&M’s Can Teach Us” (Minitab Inc., August 2008), M. Paret and E. Martz discussed several statistical analyses that they performed on bags of M&Ms. The authors took a random sample of 30 small bags of peanut M&Ms
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Explain why a census is often not the best way to obtain information about a population.
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> Use the specified grouping method to a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on your result from part (a). d. construct a relative-frequency histogram based on your resu
> An online article from the Washington Post, titled “Facebook Joins Ranks of Largest IPOs in U.S. History,” gave the following information on the top 10 IPOs (initial public offerings) in the United States as of May 2012. a. What type of data is presented
> Construct a stem-and-leaf diagram for the data, using the specified number of lines per stem. Ese two lines per stem.
> Construct a stem-and-leaf diagram for the data, using the specified number of lines per stem. Use five lines per stem.
> Construct a stem-and-leaf diagram for the data, using the specified number of lines per stem. Use one line per stem.
> Construct a stem-and-leaf diagram for the data, using the specified number of lines per stem. Use one line per stem.
> Construct a dotplot for the data.
> Construct a dotplot for the data.
> Construct a dotplot for the data.
> In the special report, “Bitter Pill: Why Medical Bills Are Killing Us” (TIME, Vol. 181, No. 8, 2013), S. Brill presented an in-depth investigation of hospital billing practices that reveals why U.S. health care spending is out of control. One of the many
> Construct a dotplot for the data.
> We have presented some quantitative data sets and specified a grouping method for practicing the concepts. For each data set, a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on
> We have presented some quantitative data sets and specified a grouping method for practicing the concepts. For each data set, a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on
> Each year, Forbes magazine publishes a list of the world’s richest people. On page 37, we constructed a table, based on a 2013 Forbes article, that shows the 25 richest people in the world, as of March of that year. a. For each of the five columns of the
> At the beginning of this chapter, we discussed the results of a survey by the American Film Institute (AFI). Now that you have learned some of the basic terminology of statistics, we want you to examine that survey in greater detail. Answer each of the f
> Almost any inferential study involves aspects of descriptive statistics. Explain why.
> This problem is about variables. a. What is a variable? b. Identify two main types of variables. c. Identify the two types of quantitative variables.
> The U.S. Geological Survey monitors and reports on earthquakes, providing daily real-time, worldwide earthquake lists. Some of the information for four of the 105 earthquakes that occurred on May 10, 2013, is shown in the following table. Magnitude is gi
> Fill in the blank: x¯ is to μ as r is to .
> Generally speaking, what is the difference between a confidence interval and a prediction interval?
> For a particular value of a predictor variable, is there a difference between the predicted value of the response variable and the point estimate for the conditional mean of the response variable? Explain your answer.
> Identify three statistics that can be used as a basis for testing the utility of a regression.
> Suppose that you perform a hypothesis test for the slope of the population regression line with the null hypothesis H0: β1 = 0 and the alternative hypothesis Ha: β1 = 0. If you reject the null hypothesis, what can you say about the utility of the regress
> Regarding analysis of residuals, decide in each case which assumption for regression inferences may be violated. a. A residual plot—that is, a plot of the residuals against the observed values of the predictor variable—shows curvature. b. A residual plot
> What two plots did we use in this chapter to decide whether we can reasonably presume that the assumptions for regression inferences are met by two variables of a population? What properties should those plots have?
> From the website Golf.com, part of Sports Illustrated Sites, we obtained the scores for the first and second rounds of the 2013 U.S. Open golf tournament. You will find those scores on the WeissStats site. - For the estimations and predictions, use a fir
> Suppose that x and y are two variables of a population and that the assumptions for regression inferences are met with x as the predictor variable and y as the response variable. a. What statistic is used to estimate the slope of the population regressio
> The National Oceanic and Atmospheric Administration publishes temperature and precipitation information for cities around the world in Climates of the World. Data on average high temperature (in degrees Fahrenheit) in July and average precipitation (in i
> We have presented some quantitative data sets and specified a grouping method for practicing the concepts. For each data set, a. determine a frequency distribution. b. obtain a relative-frequency distribution. c. construct a frequency histogram based on
> From the International Data Base, published by the U.S. Census Bureau, we obtained data on infant mortality rate (IMR) and life expectancy (LE), in years, for a sample of 60 countries. The data are presented on the WeissStats site. - For the estimations
> Refer to Problem 11. At the 2.5% significance level, do the data provide sufficient evidence to conclude that the variables student-to-faculty ratio and graduation rate are positively linearly correlated? Data from Problem 11: Graduation rate—the percen
> Refer to Problems 11 and 12. a. Find the predicted graduation rate for a university that has a student-to-faculty ratio of 17. b. Find a 95% prediction interval for the graduation rate of a university that has a student-to faculty ratio of 17. c. Explain
> Refer to Problems 11 and 12. a. Find a point estimate for the mean graduation rate of all universities that have a student-to faculty ratio of 17. b. Determine a 95% confidence interval for the mean graduation rate of all universities that have a student
> Refer to Problems 11 and 12. a. At the 5% significance level, do the data provide sufficient evidence to conclude that student to-faculty ratio is useful as a predictor of graduation rate? b. Determine a 95% confidence interval for the slope, β1, of the