Question: Is the mean IQ of the students

> A “nine-ender” is an individual whose age ends in 9 (as in 29, 39, 49 years of age). Some studies have suggested that nine-enders tend to participate in certain activities at a higher rate than those whose age ends in the digits 0 through 8. For example,

> If the expected count of a category is less than 1, what can be done to the categories so that a goodness-of-fit test can still be performed?

> Explain why chi-square goodness-of-fit tests are always right tailed.

> Why is goodness of fit a good choice for the title of the procedures used in this section?

> How much does the typical person pay for a new 2019 Audi A4? The following data represent the selling price of a random sample of new A4s (in dollars). (a) Is this data quantitative or qualitative? (b) Find the mean and median price of a new 2019 A4. (c)

> On February 2, 1894, Frank Raphael Weldon wrote a letter to Francis Galton that included the results of 26,306 rolls of 12 dice. Weldon recorded the results such that a roll of a 5 or 6 resulted in a success, while a roll of 1, 2, 3, or 4 was a failure.

> In Thomas Pynchon’s book Gravity Rainbow, the characters discuss whether the Poisson probabilistic model can be used to describe the locations that Germany’s feared V-2 rocket would land in. They divided London into 0.25-km2 regions. They then counted th

> Write two questions that could have different responses, depending on the order in which the questions are presented. Or write a single question such that the order in which words are presented could affect the response. Administer the survey to at least

> In 2000, 25.8% of Americans 15 years of age or older lived alone, according to the Census Bureau. A sociologist, who believes that this percentage is greater today, conducts a random sample of 400 Americans 15 years of age or older and finds that 164 are

> According to the U.S. Census Bureau, 7.1% of all babies born are of low birth weight 1 65 lb, 8 oz2. An obstetrician wanted to know whether mothers between the ages of 35 and 39 years give birth to a higher percentage of low-birth-weight babies. She rand

> An urban economist wonders if the distribution of U.S. residents in the United States is different today than it was in 2000. The table shows the distribution of residents in 2000 along with the observed counts of residents today based on a random sample

> At Joliet Junior College, the mathematics department decided to offer a redesigned course in Intermediate Algebra, called the Math Redesign Program (MRP). Laura Egner, the coordinator of the program, wanted to determine if the grade distribution in the c

> A researcher wanted to determine whether pedestrian deaths were uniformly distributed over the days of the week. She randomly selected 300 pedestrian deaths, recorded the day of the week on which the death occurred, and obtained the following results (th

> Do people cheat or lie when the cheating or lying is not easy to identify (such as filing of taxes)? A total of 2568 college-aged subjects from various countries throughout the world rolled a single six-sided die twice. The subjects were told that the

> A researcher wanted to determine whether bicycle deaths were uniformly distributed over the days of the week. She randomly selected 200 deaths that involved a bicycle, recorded the day of the week on which the death occurred, and obtained the following r

> In his book Outliers, Malcolm Gladwell claims that more hockey players are born in January through March than in October through December. The following data show the number of players in the National Hockey League in the 2018–2019 season according to

> On January 1, 2004, it became mandatory for all police departments in Illinois to record data pertaining to race from every traffic stop. Mundelein, Illinois, has been collecting data since 2000. Rather than using census data to determine the racial dist

> Does the location of your seat in a classroom play a role in attendance or grade? To answer this question, professors randomly assigned 400 students* in a general education physics course to one of four groups. *The number of students was increased so th

> Write a survey question that contains strong wording and one that contains tempered wording. Post each question in an online survey site such as StatCrunch, surveymonkey.com, or polldaddy.com. Administer the survey to at least 25 different people for eac

> Is the religious make-up of the United States Congress reflective of that in the general population? The following table shows the religious affiliation of the 535 members of the 116th Congress along with the religious affiliation of a random sample of 1

> The National Highway Traffic Safety Administration publishes reports about motorcycle fatalities and helmet use. The distribution shows the proportion of fatalities by location of injury for motorcycle accidents. (a) Does the distribution of fatal injuri

> Refer to Problem 13. The distribution in the next column lists the first digit of the surface area (in square miles) of 335 rivers. Is there evidence at the  = 0.05 level of significance to support the belief that the distribution follows Benford’s La

> Our number system consists of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. The first significant digit in any number must be 1, 2, 3, 4, 5, 6, 7, 8, or 9 because we do not write numbers such as 12 as 012. Although we may think that each 1 first digit app

> According to the manufacturer of M&Ms, 12% of the peanut M&Ms in a bag should be brown, 15% yellow, 12% red, 23% blue, 23% orange, and 15% green. A student randomly selected a bag of peanut M&Ms. He counted the number of M&Ms that were each color and obt

> According to the manufacturer of M&Ms, 13% of the plain M&Ms in a bag should be brown, 14% yellow, 13% red, 24% blue, 20% orange, and 16% green. A student randomly selected a bag of plain M&Ms. He counted the number of M&Ms that were each color and obtai

> H0: The random variable X is binomial with n = 4, p = 0.3 H1: The random variable X is not binomial with n = 4, p = 0.3

> H0: The random variable X is binomial with n = 4, p = 0.8 H1: The random variable X is not binomial with n = 4, p = 0.8

> H0: pA = pB = pC = pD = pE = 1/5 H1: At least one of the proportions is different from the others.

> H0: pA = pB = pC = pD = 1/4 H1: At least one of the proportions is different from the others.

> In the early 1990s, Gallup asked Americans whether they supported the United States bombing Serbian forces in Bosnia. In this survey, 35% of respondents supported the idea. The very same day, ABC News asked whether Americans would support the United Stat

>

>

> What are the two requirements that must be satisfied to perform a goodness-of-fit test?

> Suppose there are n independent trials of an experiment with k > 3 mutually exclusive outcomes, where pi represents the probability of observing the ith outcome. The______ for each possible outcome are given by Ei =________ .

> The following data represent the measure of a variable before and after a treatment. Does the sample evidence suggest that the treatment is effective in increasing the value of the response variable? Use the  = 0.05 level of significance. Note: Assume t

> A random sample of size n = 41 results in a sample mean of 125.3 and a sample standard deviation of 8.5. An independent sample of size n = 50 results in a sample mean of 130.8 and sample standard deviation of 7.3. Does this constitute sufficient evidence

> A random sample of n1 = 135 individuals results in x1 = 40 successes. An independent sample of n2 = 150 individuals results in x2 = 60 successes. Does this represent sufficient evidence to conclude that p1 6 p2 at the  = 0.05 level of significance?

> A random sample of size n = 13 obtained from a population that is normally distributed results in a sample mean of 45.3 and sample standard deviation of 12.4. An independent sample of size n = 18 obtained from a population that is normally distributed

> A random sample of n1 = 120 individuals results in x1 = 43 successes. An independent sample of n2 = 130 individuals results in x2 = 56 successes. Does this represent sufficient evidence to conclude that p1≠ p2 at the a = 0.01 level of significance?

> Do recent graduates from college who have no debt start their own business at a higher rate than recent graduates who have debt between $20,000 and $40,000?

> Develop a survey that you could administer using online survey tools such as StatCrunch, surveymonkey.com, or polldaddy.com. Administer the survey. Did the responses accurately reflect the goals of each question? What types of nonsampling error did you e

> By how much does adiposity (a measure of body fat) differ between adult women who maintain a regular sleep schedule versus women whose sleep schedule fluctuates by 90 minutes or more?

> While exercising by climbing stairs, is it better to take one stair, or two stairs, at a time? Researchers identified 30 volunteers who were asked to climb stairs for two different 15-minute intervals taking both one stair and two stairs at a time. Wheth

> Does turmeric (an antioxidant that can be added to foods) help with depression? Researchers randomly assigned 200 adult women who were clinically depressed to two groups. Group 1 had turmeric added to their regular diet for one week; group 2 had no addit

> Does drinking two cups of water before a meal assist with weight loss?

> What proportion of registered voters is in favor of a tax increase to reduce the federal debt?

> What is the typical amount of time 20- to 24-year-old males spend brushing their teeth (each time they brush)?

> Does Marriott Courtyard charge more than Holiday Inn Express for a one-night stay?

> Do adult males who take a single aspirin daily experience a lower rate of heart attacks than adult males who do not take aspirin daily?

> Refer to the data in Problem 12. Treat the data as an independent sample. Compute the sample mean difference and standard error of this data. Compute the sample mean difference and standard error treating the data as a dependent sample. What do the resul

> During every election, pollsters conduct exit interviews to help determine which candidate people voted for. During the 2016 presidential election, exit polls under-sampled the number of voters called “Democrat white working-class voters” and over-sample

> It has long been a concern that there is a wage gap between men and women in the United States with some reports suggesting that women only make $0.77 for every dollar earned by a man. Design a study that would allow you to confirm whether a wage gap doe

> John has an online company that sells custom rims for cars. A web-design firm hired by John designed two different web pages to be used to sell his rims online. However, he cannot decide which page to go with, so he decides to collect some data. John hir

> In the fall of 1998, the National Center for Education Statistics (NCES) established a cohort of kindergarten students based on a random sample of all kindergarten students throughout the United States. Objective reading and math assessments were adminis

> As of October 1, 2012, hospitals in the United States with excessive numbers of readmissions based on the Centers for Medicare and Medicaid Services (CMS) data were penalized. Therefore, it is important for hospitals to identify the risk factors associat

> The data below represent the 5-year rate of return (in percent) for a random sample of stocks in financial services and an independent random sample of stocks in health care. Has there been a difference in the rate of return of companies in the Financial

> In today’s “wired” society, students believe that they can multitask. Research suggests that 5% of individuals truly have the ability to multitask. Can students multitask, or do they perform worse while multitasking? In an introductory accounting class,

> Is there a difference in the attitude toward extramarital affairs in the United States versus Canada? Pew Research surveyed a random sample of adults from each country and asked, “Do you personally believe that married people having an affair is morally

> The Pew Research Group asked the following question of individuals who earned in excess of $100,000 per year and those who earned less than $100,000 per year: “Do you believe that it is morally wrong for unwed women to have children?” Of the 1205

> In a study published in the journal Teaching of Psychology, the article “Fudging the Numbers: Distributing Chocolate Influences Student Evaluations of an Undergraduate Course” states that distributing chocolate to students prior to teacher evaluations

> Researchers conducted an experiment in which 695 individuals were shown black and white photographs of individuals running for Congress (either the U.S. Senate or House of Representatives). In each instance, the individuals were exposed to the photogra

> In the federal government’s Current Population Survey, the response rate for 20- to 29-year- olds is 85%; for individuals at least 70 years of age it is 99%. Why do you think this is?

> Do wet suits allow a swimmer to swim faster? Researchers measured the speed (in meters per second) of swimmers both with and without a wetsuit. The results of the study are shown in the table. Conduct the appropriate test to determine whether the data su

> The average major league fastball is 92.0 miles per hour (mph). While there are many other factors other than velocity that are used to judge the quality of this pitch (location and movement, for example), velocity is a major factor in deciding whether a

> Do people tend to spend more money on fast-food when they use a credit card? The following data represent a random sample of credit-card and cash purchases. (a) Draw boxplots of each data set using the same scale. What do the boxplots imply for cash vers

> What is the typical age difference between husband and wife? The following data represent the ages of husbands and wives, based on results from the Current Population Survey. (a) What is the response variable in this study? (b) Is the sampling method dep

> TIMS is an acronym for the Third International Mathematics and Science Study. Kumon promotes a method of studying mathematics that it claims develops mathematical ability. Do data support this claim? In one particular question on the TIMS exam, a random

> Automobile collision insurance is used to pay for any claims made against the driver in the event of an accident. This type of insurance will typically pay to repair any assets that your vehicle damages. (a) Collision claims tend to be skewed right. Why

> The following data represent the measure of a variable before and after a treatment. Does the sample evidence suggest that the treatment is effective in decreasing the value of the response variable? Use the  = 0.10 level of significance. Note: Assume t

> (a) Test whether /level of significance for the given sample data. (b) Construct a 95% confidence interval about /

> Explain why using the smaller of / degrees of freedom to determine the critical t instead of Formula (2) is conservative.

> In a MythBusters episode, the question was asked, “Which is better? A four-way stop or a roundabout?” “Better” was determined based on determining the number of vehicles that travel through the four-way stop over a 5-minute interval of time. Suppose the

> The Telephone Consumer Protection Act (TCPA) allows consumers to put themselves on a do-not-call registry. If a number is on the registry, commercial telemarketers are not allowed to call you. Do you believe this has affected the ability of surveyors to

> The Collegiate Learning Assessment Plus (CLA+) is an exam that is meant to assess the intellectual gains made between one’s freshman and senior year of college. The exam, graded on a scale of 400 to 1600, assesses critical thinking, analytical reasoning,

> PayScale reports statistics on colleges and universities. Go to www.pearsonhighered.com/ sullivanstats to obtain the data file 11_3_24 using the file format of your choice for the version of the text you are using. The data contain the four-year cost and

> Professor Stephen Zuro of Joliet Junior College wanted to determine whether an online homework system (meaning students did homework online and received instant feedback with helpful guidance about their answers) improved scores on a final exam. In the f

> Bottles The aluminum bottle, first introduced in 1991 by CCL Container for mainly personal and household items such as lotions, has become popular with beverage manufacturers. Besides being lightweight and requiring less packaging, the aluminum bottle i

> Young children require a lot of time and this time commitment cuts into a parent’s leisure time. A sociologist wanted to estimate the difference in the amount of daily leisure time (in hours) of adults who do not have children under the age of 18 years a

> Do women feel differently from men when it comes to federal tax rates? One question on the Sullivan Statistics Survey II was, “What percent of income do you believe individuals should pay in federal income tax?” Results of the survey may be found at www.

> Stocks may be categorized by sectors. Go to www.pearsonhighered.com/sullivanstats to obtain the data file 11_3_19 using the file format of your choice for the version of the text you are using. The data represent the one- year rate of return (in percent)

> The website touringplans.com records actual wait times (in minutes) for the Pirates of the Caribbean ride and Splash Mountain ride at Walt Disney World. Do the wait times at these two rides differ? (a) To answer this question, a random sample of wait tim

> The data set “Tornadoes_2017” located at www.pearsonhighered.com/ sullivanstats contains a variety of variables that were measured for all tornadoes in the United States in 2017. (a) Is there a difference in the length of tornadoes in Texas versus Georgi

> Researchers wanted to know whether there was a difference in comprehension among students learning a computer program based on the style of the text. They randomly divided 36 students of similar educational level, age, and so on, into two groups of 18 ea

> According to Martin Boon of ICM Limited, a polling firm in Britain, in 1995 it took 3000 to 4000 phone calls to obtain a sample of size 2000. Today, it takes over 30,000 calls. To reduce costs, more polling is done using robocalls and Internet-based poll

> Student ID number

> Researchers wanted to determine if carpeted rooms contained more bacteria than uncarpeted rooms. To determine the amount of bacteria in a room, researchers pumped the air from the room over a Petri dish at the rate of 1 cubic foot per minute for eight ca

> Researchers wanted to determine whether the reaction time (in seconds) of males differed from that of females to a go/no go stimulus. The researchers randomly selected 20 females and 15 males to participate in the study. The go/no go stimulus required th

> Ramp metering is a traffic engineering idea that requires cars entering a freeway to stop for a certain period of time before joining the traffic flow. The theory is that ramp metering controls the number of cars on the freeway and the number of cars acc

> Researchers Brian Wansink and Junyong Kim randomly gave 157 moviegoers a free medium (120 grams) or large (250 gram) bucket of popcorn before entering a movie. After the show, the researchers measured how much popcorn the moviegoers consumed. The 77 indi

> Two Dutch researchers conducted a study in which two groups of students were asked to answer 42 questions from Trivial Pursuit. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a professor, while the students

> Do business travelers walk at a different pace than leisure travelers? Researcher Seth B. Young measured the walking speed of business and leisure travelers in San Francisco International Airport and Cleveland Hopkins International Airport. His findings

> Do people walk faster in the airport when they are departing (getting on a plane) or when they are arriving (getting off a plane)? Researcher Seth B. Young measured the walking speed of travelers in San Francisco International Airport and Cleveland Hopki

> Testosterone is a steroid in men that affects sex drive, bone, and muscle mass. Researchers wanted to determine the impact of marriage on testosterone levels in males. Source: Stine A. Hogmboe et. al., “Influence of Marital Status on Testosterone Levels—

> A researcher with the Department of Education followed a cohort of students who graduated from high school in 1992, monitoring the progress the students made toward completing a bachelor’s degree. One aspect of his research was to determine whether stude

> Test whether / level of significance for the given sample data.

> Many national polls are based on random-digit dialing (RDD). In this method, a computer randomly generates a phone number in the hopes of reaching an individual at his/her residence. In registration-based sampling (RBS), voter files are used to obtain a

> Test whether /level of significance for the given sample data.

> (a) Test whether /level of significance for the given sample data. (b) Construct a 95% confidence interval about /

> (a) Test whether /level of significance for the given sample data. (b) Construct a 90% confidence interval about /

> (a) Test whether /level of significance for the given sample data. (b) Construct a 95% confidence interval about /