Question: What percentage of the time will a

> A study of fast-food intake is described in the paper “what people buy from fast-food restaurants” (Obesity [2009]:1369–1374). Adult customers at three hamburger chains (McDonald’s, Burger King, and Wendy’s) in New York City were approached as they enter

> Suppose that the researchers who carried out the study described in the previous exercise wanted to estimate the mean following distance with a margin of error of 0.2 meters. Using the given sample standard deviation as a preliminary estimate of the popu

> The authors of the paper “Driving performance while Using a mobile phone: a Simulation Study of greek professional Drivers” (Transportation Research Part F [2016]: 164–170) describe a study to evaluate the effect of mobile phone use by taxi drivers in Gr

> How much money do people spend on graduation gifts? In 2016, the national retail federation (www.nrf.com) surveyed 2511 consumers who reported that they bought one or more graduation gifts in 2016. The sample was selected to be representative of adult Am

> The authors of the paper “Serum Zinc Levels of cord blood: relation to birth weight and gestational period” (Journal of Trace Elements in Medicine and Biology [2015]: 180–183) carried out a study of zinc levels of low-birth-weight babies and normal-birth

> Suppose that a random sample of 50 cans of a particular brand of fruit juice is selected, and the amount of juice (in ounces) in each of the cans is determined. Let µ denote the mean amount of juice for the population of all cans of this brand. Suppose t

> The article “the association between television Viewing and irregular Sleep Schedules among children Less than 3 Years of age” (Pediatrics [2005]: 851–856) reported the accompanying 95% confidence int

> Let x represent the time (in minutes) that it takes a fifth grade student to read a certain passage. Suppose that the mean and standard deviation of the x distribution are µ = 2 minutes and σ = 0.8 minutes, respectively. a. If x is the sample mean time

> Suppose that college students with a checking account typically write relatively few checks in any given month, whereas people who are not college students typically write many more checks during a month. Suppose that 50% of a bank’s accounts are held by

> Major League Baseball (MLB) includes two groups of teams, in “leagues.” There are 15 teams in each of the American League (AL) and the National League (NL). Since 1997, teams in each of the leagues play teams from the

> Exercise 12.44 asks whether a representative sample of Big Mac prices (after conversion to U.S. dollars) from countries in Europe provides evidence that the mean European price is less than the reported U.S. price of $5.04. Here are the data: a. What cha

> Researchers studied ergometer (rowing machine) time (in seconds) for international male competitors in the 2007 World Junior Rowing Championships. They found that the mean time to row 2000 meters on an ergometer for the population of international sculls

> Consumer Reports provides ratings for televisions, including energy cost per year (in dollars) (www.consumerreports.org/products/lcd-led-oled-tvs/ratings-overview/, retrieved December 23, 2016). Energy cost data for a sample of 13 small televisions (29-i

> Teams in the National Football League (NFL) are given a “bye” during one week of the season, when they can rest and not play a game. This may provide an advantage for the team in the next game they play after a bye. I

> Example 12.12 provided the following 21-time discrimination scores for male smokers who had abstained from smoking for 24 hours. a. What characteristic of the sample size indicates that the methods based on the t distribution may not be appropriate? b.

> The dodo was a species of flightless bird that lived on the island of Mauritius in the Indian Ocean. The first record of human interaction with the dodo occurred in 1598, and within 100 years the dodo was extinct due to hunting by humans and other newly

> Consumer Reports published the following gas mileage values (Overall MPG) for a sample of electric or plugin hybrid car models (www.consumerreports.org/cro/cars /new-cars/hybrids-evs/ratings-reliability/ratings-overview. htm, retrieved December 23, 2016)

> A hot tub manufacturer advertises that a water temperature of 100°F can be achieved in 15 minutes or less. A random sample of 25 tubs is selected, and the time necessary to achieve a 100°F temperature is determined for each tub. The sample mean time and

> A student organization uses the proceeds from a soft drink vending machine to finance its activities. The price per can was $0.75 for a long time, and the mean daily revenue during that period was $75.00. The price was recently increased to $1.00 per can

> An automobile manufacturer decides to carry out a fuel efficiency test to determine if it can advertise that one of its models achieves 30 mpg (miles per gallon). Six people each drive a car from Phoenix to Los Angeles. The resulting fuel efficiencies (i

> USA TODAY (October 14, 2016) reported that Americans spend 4.1 hours per weekday checking work e-mail. This was an estimate based on a survey of 1004 white-collar workers in the United States. a. Suppose that you would like to know if there is evidence

> People in a random sample of 236 students enrolled at a liberal arts college were asked questions about how much sleep they get each night (“alcohol consumption, Sleep, and academic performance among college Students,” Journal of Studies on Alcohol and D

> The authors of the paper “mean platelet Volume could be possible biomarker in early Diagnosis and monitoring of gastric cancer” (Platelets [2014]: 592–594) wondered if mean platelet volume (MPV) might be a way to distinguish patients with gastric cancer

> The eating habits of n = 12 bats were examined in the article “foraging behavior of the indian false Vampire bat” (Biotropica [1991]: 63–67). These bats consume insects and frogs. For these 12 bats, the mean time to consume a frog was x = 21.9 minutes. S

> Give as much information as you can about the P-value of a t test in each of the following situations: a. Two-tailed test, n = 16, t = 1.6 b. Upper-tailed test, n = 14, t = 3.2 c. Lower-tailed test, n = 20, t = -5.1 d. Two-tailed test, n = 16, t = 6.

> Many consumers pay careful attention to stated nutritional contents on packaged foods when making purchases, so it is important that the information on packages be accurate. Suppose that a random sample of n = 12 frozen dinners of a certain type was sele

> The authors of the paper “changes in Quantity, Spending, and nutritional characteristics of adult, adolescent and child Urban corner Store purchases after an environmental intervention” (Preventative Medicine [2015]: 81–85) wondered if increasing the ava

> The report “majoring in money: how american college Students manage their finances” (Salliemae, 2016, www.news/salliemae.com, retrieved December 24, 2106) includes data from a survey of college students. Each person in a representative sample of 793 coll

> The report “2016 Salary Survey executive Summary” (national association of colleges and employers, www.naceweb.org/uploadedfiles/files/2016/publications/executivesummary/2016-nace-salary-survey-fall-executive-summary. pdf, retrieved December 24, 2016) s

> Give as much information as you can about the P-value of a t test in each of the following situations: a. Two-tailed test, df = 9, t = 0.73 b. Upper-tailed test, df = 10, t = 0.5 c. Lower-tailed test, n = 20, t = -2.1 d. Two-tailed test, n = 40, t =

> The paper titled “music for pain relief” (The Cochrane Database of Systematic Reviews, april 19, 2006) concluded, based on a review of 51 studies of the effect of music on pain intensity, that “Listening to music reduces pain intensity levels … However,

> In a study of media use, each person in a large representative sample of male Canadian high school students was asked how much time they spent playing video or computer games (in minutes per day). The sample mean was 123.4 minutes and the sample standard

> The Economist collects data each year on the price of a Big Mac in various countries around the world. A sample of McDonald’s restaurants in Europe in July 2016 resulted in the following Big Mac prices (after conversion to U.S. dollars)

> The paper referenced in the previous exercise also states that the known mean resting heart rate for boys in this age group is 66 bpm. a. Is there convincing evidence that the mean heart rate after Wii Bowling for 15 minutes is higher than the known mea

> The paper “playing active Video games increases energy expenditure in children” (Pediatrics [2009]: 534–539) describes a study of the possible cardiovascular benefits of active video games. Mean heart rate for healthy boys ages 10 to 13 after walking on

> Give as much information as you can about the P-value of a t test in each of the following situations. (Hint: See discussion on page 594.) a. Upper-tailed test, df = 8, t = 2.0 b. Lower-tailed test, df = 10, t = -2.4 c. Lower-tailed test, n = 22, t =

> The article “americans’ big Debt burden growing, not evenly Distributed” (www.gallup.com, retrieved December 14, 2016) reported that for a representative sample of Americans born between 1965 and 1971 (known as Generation X), the sample mean number of cr

> Use the information given in the previous exercise to construct a 95% confidence interval for the mean number of partners on a mating flight for queen honeybees. For purposes of this exercise, assume these 30 queen honeybees are representative of the pop

> The paper “the curious promiscuity of Queen honey bees (Apis mellifera): evolutionary and behavioral mechanisms” (Annals of Zoology [2001]:255–265) describes a study of the mating behavior of queen honeybees. The following quote is from the paper: Queen

> Five students visiting the student health center for a free dental examination during National Dental Hygiene Month were asked how many months had passed since their last visit to a dentist. Their responses were: Assuming that these five students can be

> Consumer Reports gave the following mileage ratings (in miles per gallon) for seven midsize hybrid 2016 model cars (www.consumerreports.org/cro/cars/new-cars /hybrids-evs/ratings-reliability/ratings-overview.htm, retrieved December 21, 2016). Is it reaso

> The formula used to calculate a confidence interval for the mean of a normal population when n is small is /What is the appropriate t critical value for each of the following confidence levels and sample sizes? a. 95% confidence, n = 15 b. 99% confiden

> What percentage of the time will a variable that has a t distribution with the specified degrees of freedom fall in the indicated region? a. 5 df, between -2.02 and 2.02 b. 14 df, between -2.98 and 2.98 c. 22 df, outside the interval from -1.72 to 1.7

> Because of safety considerations, in May 2003, the Federal Aviation Administration (FAA) changed its guidelines for how small commuter airlines must estimate passenger weights. Under the old rule, airlines used 180 pounds as a typical passenger weight (i

> A manufacturer of college textbooks is interested in estimating the strength of the bindings produced by a particular binding machine. Strength can be measured by recording the force required to pull the pages of a book from its binding. If this force is

> Acrylic bone cement is sometimes used in hip and knee replacements to secure an artificial joint in place. The force required to break an acrylic bone cement bond was measured for six specimens, and the resulting mean and standard deviation were 306.09 N

> USA TODAY reported that the average amount of money spent on coffee drinks each month is $78.00 (USA Snapshot, November 4, 2016). a. Suppose that this estimate was based on a representative sample of 20 adult Americans. Would you recommend using the one

> Samples of two different models of cars were selected, and the actual speed for each car was determined when the speedometer registered 50 mph. The resulting 95% confidence intervals for mean actual speed were (51.3, 52.7) for model 1 and (49.4, 50.6) fo

> The formula used to calculate a confidence interval for the mean of a normal population is What is the appropriate t critical value for each of the following confidence levels and sample sizes? a. 90% confidence, n = 12 b. 90% confidence, n = 25 c. 95

> The authors of the paper “Beyond the Shooter Game: Examining Presence and Hostile Outcomes among Male Game Players” (Communication Research [2006]: 448–466) studied how video game content might influe

> The paper referenced in Exercise 16.3 described an experiment to determine if restrictive age labeling on video games increased the attractiveness of the game for boys ages 12 to 13. In that exercise, the null hypothesis was H0: µ1 = Â

> Can use of an online plagiarism-detection system reduce plagiarism in student research papers? The paper “Plagiarism and Technology: A Tool for Coping with Plagiarism” ( Journal of Education for Business [2005]: 149&ac

> The paper “women’s and men’s eating behavior Following exposure to ideal-body images and text” (Communication Research [2006]: 507–529) describes an experiment in w

> Consider the accompanying data on plant growth after the application of five different types of growth hormone. a. C arry out the ANOVA F test using a significance level of  = 0.05. b. What happens when the T-K procedure is applied?

> In an experiment to investigate the effect of the portrayal of female characters in superhero movies, researchers randomly assigned female college students to one of three groups (“the empowering (super) heroine? the effects of sexualiz

> Suppose that samples of six different brands of diet or imitation margarine were analyzed to determine the level of physiologically active polyunsaturated fatty acids (PAPUFA, in percent), resulting in the accompanying data. a. Carry out a test to dete

> Do lizards play a role in spreading plant seeds? Some research carried out in South Africa would suggest so (“Dispersal of namaqua Fig [Ficus cordata cordata] seeds by the augrabies Flat lizard [Platysaurus broadleyi],â€&#157

> The paper referenced in the Exercise 16.15 also gave the following underscoring pattern for men. a. Write a few sentences interpreting this underscoring pattern. b. Using your answers from Part (a) and from the Exercise 16.15, write a few sentences de

> The paper “trends in blood lead levels and blood lead testing among U.s. children aged 1 to 5 Years” (Pediatrics [2009]: e376–e385) gave data on blood lead levels (in mg/dL) for samples of children li

> The following data resulted from a flammability study in which specimens of five different fabrics were tested to determine burn times (in seconds). The accompanying output gives the T-K intervals as calculated by Minitab. Identify significant differen

> The accompanying underscoring pattern appears in the article “women’s and men’s eating behavior Following exposure to ideal-body images and text” (Communications Research [2006]: 507

> Leaf surface area is an important variable in plant gas-exchange rates. Dry matter per unit surface area (mg/ cm3) was measured for trees raised under three different growing conditions. Let m1, m2, and m3 represent the mean dry matter per unit surface a

> Parents are frequently concerned when their child seems slow to begin walking (although when the child finally walks, the resulting havoc sometimes has the parents wishing they could turn back the clock!). The article “walking in the ne

> It is common for baseball pitchers to use stretching to prepare for a game. But does this make a difference? The authors of the paper “the acute effects of Upper extremity stretching on throwing velocity in baseball throwersâ&#128

> The chapter Preview Example described a study comparing three groups of college students (soccer athletes, nonsoccer athletes, and a comparison group consisting of students who did not participate in intercollegiate sports). The following is information

> The accompanying summary statistics for a measure of social marginality for samples of youths, young adults, adults, and seniors appeared in the paper “Perceived causes of loneliness in adulthood” (Journal of Social Be

> Do people feel hungrier after sampling a healthy food? The authors of the paper “when healthy Food makes You hungry” (Journal of Consumer Research [2010]: s34–s44) carried out a study to answer this q

> In an experiment to investigate the performance of four different brands of spark plugs intended for use on a 125-cc motorcycle, five plugs of each brand were tested, and the number of miles (at a constant speed) until failure was observed. A partially c

> The experiment described in Example 16.4 also gave data on change in body fat mass for men (“growth hormone and sex steroid administration in healthy aged women and men,” Journal of the American Medical Association [20

> The paper referenced in Exercise 16.3 also gave data for 12- to 13-year-old girls. Data consistent with summary values in the paper are shown below. Do the data provide convincing evidence that the mean rating associated with the game description for 12-

> Give as much information as you can about the P-value of the single-factor ANOVA F test in each of the following situations. a. k = 5, n1 = n2 = n3 = n4 = n5 = 4, F = 5.37 b. k = 5, n1 = n2 = n3 = 5, n4 = n5 = 4, F = 2.83 c. k = 3, n1 = 4, n2 = 5, n3

> The authors of the paper “Reading Subtitles and Taking Enotes While Learning Scientific Materials in a Multimedia Environment” (Educational Technology and Society [2016): 47–58) were interested in det

> The authors of the paper “Age and Violent Content Labels Make Video Games Forbidden Fruits for Youth” (Pediatrics [2009]: 870–876) carried out an experiment to determine if restrictive labels on video

> Employees of a certain state university system can choose from among four different health plans. Each plan differs somewhat from the others in terms of hospitalization coverage. Four random samples of recently hospitalized individuals were selected, eac

> Give as much information as you can about the P-value for an upper-tailed F test in each of the following situations. a. df1 = 4, df2 = 15, F = 5.37 b. df1 = 4, df2 = 15, F = 1.90 c. df1 = 4, df2 = 15, F = 4.89 d. df1 = 3, df2 = 20, F = 14.48 e. df1

> The paper “patterns and composition of weight change in college freshmen” (College Student Journal [2015]: 553–564) reported that the freshman year weight gain for the students in a representative sample of 103 freshmen at a midwestern university was 5.7

> The Bureau of Alcohol, Tobacco, and Firearms (ATF) has been concerned about lead levels in California wines. In a previous testing of wine specimens, lead levels ranging from 50 to 700 parts per billion were recorded. How many wine specimens should be te

> The paper referenced in the previous exercise also reported that for a representative sample of 68 second-year students at the university, the sample mean procrastination score was 41.00 and the sample standard deviation was 6.82. a. Construct a 95% con

> Students in a representative sample of 65 first-year students selected from a large university in England participated in a study of academic procrastination (“Study goals and procrastination tendencies at Different Stages of the Undergraduate Degree,” S

> The paper “the effects of adolescent Volunteer activities on the perception of Local Society and community Spirit mediated by Self-conception” (Advanced Science and Technology Letters [2016]: 19–23) describes a survey of a large representative sample of

> The two intervals (114.4, 115.6) and (114.1, 115.9) are confidence intervals for µ = mean resonance frequency (in hertz) for all tennis rackets of a certain type. The two intervals were calculated using the same sample data. a. What is the value of the

> The formula used to calculate a confidence interval for the mean of a normal population is What is the appropriate t critical value for each of the following confidence levels and sample sizes? a. 95% confidence, n = 17 b. 99% confidence, n = 24 c. 90

> What percentage of the time will a variable that has a t distribution with the specified degrees of freedom fall in the indicated region? (Hint: See discussion on page 581.) a. 10 df, between -1.81 and 1.81 b. 24 df, between -2.06 and 2.06 c. 24 df,

> An airplane with room for 100 passengers has a total baggage limit of 6000 pounds. Suppose that the weight of baggage checked by an individual passenger, x, has a mean of 50 pounds and a standard deviation of 20 pounds. If 100 passengers will board a fli

> A manufacturing process is designed to produce bolts with a diameter of 0.5 inches. Once each day, a random sample of 36 bolts is selected and the bolt diameters are recorded. If the resulting sample mean is less than 0.49 inches or greater than 0.51 inc

> Suppose that a random sample of size 100 is to be drawn from a population with standard deviation 10. a. What is the probability that the sample mean will be within 20 of the value of m? b. F or this example (n = 100, σ = 10), complete each of the foll

> Suppose that the population mean value of interpupillary distance (the distance between the pupils of the left and right eyes) for adult males is 65 mm and that the population standard deviation is 5 mm. a. If the distribution of interpupillary distance

> A sign in the elevator of a college library indicates a limit of 16 persons. In addition, there is a weight limit of 2500 pounds. Assume that the average weight of students, faculty, and staff at this college is 150 pounds, that the standard deviation is

> Explain the difference between x and µ x.

> For which of the sample sizes given in the previous exercise would it be reasonable to think that the sampling distribution of x is approximately normal in shape?

> A random sample is selected from a population with mean µ = 200 and standard deviation σ = 15. Determine the mean and standard deviation of the sampling distribution of x for each of the following sample sizes: a. n = 12 b. n = 20 c. n = 25 d. n = 40

> Suppose that a random sample of size 64 is to be selected from a population with mean 40 and standard deviation 5. a. What are the mean and standard deviation of the sampling distribution of x? Describe the shape of the sampling distribution of x? b. Wh

> Explain the difference between σ and σx.

> The paper “alcohol consumption, Sleep, and academic performance among college Students” (Journal of Studies on Alcohol and Drugs [2009]: 355–363) describes a study of n = 236 students that were random

> For which of the sample sizes given in the previous exercise would it be reasonable to think that the x sampling distribution is approximately normal in shape?

> A random sample is selected from a population with mean µ = 60 and standard deviation σ = 3. Determine the mean and standard deviation of the sampling distribution of x for each of the following sample sizes: a. n = 6 b. n = 18 c. n = 42 d. n = 75 e

> The time that people have to wait for an elevator in an office building has a uniform distribution over the interval from 0 to 1 minute. For this distribution, µ = 0.5 and σ = 0.289. a. If x is the average waiting time for a random sample of n = 16 wait

> Explain the difference between µ and µx.

> The paper “alcohol consumption, Sleep, and academic performance among college Students” ( Journal of Studies on Alcohol and Drugs [2009]: 355–363) describes a study of n = 236 students who were random

> For which of the sample sizes given in the previous exercise would it be reasonable to think that the x sampling distribution is approximately normal in shape?