(Exercise 2.45 revisited) Is there brand loyalty among car owners in their purchases of gasoline? To help answer the question, a random sample of car owners was asked to record the brand of gasoline in their last two purchases: 1 = Exxon, 2 = Amoco,3 = Texaco, 4 = Other. Can we conclude that there is brand loyalty in gasoline purchases?
> Does education play a role to explain the results in Exercise 13.59. a. Test to determine whether there is enough evidence to infer that Republicans (PARTYID3: 1 = Democrat; 3 = Republican) more educated than Democrats (EDUC). b. Estimate the difference
> Refer to Exercise 13.59. If it is true that Republicans (PARTYID3: 1 = Democrat; 3 = Republican) have higher incomes than Democrats, is it because they work harder? a. Conduct a statistical test to determine whether Republicans work longer hours (HRS1).
> Republicans tend to prefer smaller less intrusive government and lower taxes. Is this because Republicans have higher incomes (PARTYID3: 1 = Democrat; 3 = Republican)? a. Do the data allow us to conclude that Republicans earn more income (RINCOME) than D
> In most countries including the United States, younger people tend to be on the left side of the political spectrum. If so, we would expect Republicans to be older than Democrats. a. Conduct a test to determine whether there is enough evidence to infer t
> The relationship between drug companies and medical researchers is under scrutiny because of possible conflict of interest. The issue that started the controversy was a 1995 case control study that suggested that the use of calcium-channel blockers to tr
> For Exercise 15.5, retest the hypotheses, assuming that the experiment involved twice as many trials (n = 300) and that the observed frequencies were twice as high as before, as shown here. Cell 1 2 3 4 Frequency 76 100 76 48
> Because many immigrants come to the United States with little money they often are willing to take risks that can result in high incomes. However, is this enough to overcome language and culture difficulties? a. Is there sufficient evidence to infer that
> Immigration has become an important topic in American politics. Some immigrants came to the United States to do jobs that Americans do not want to do. Many of these immigrants have little formal education. Other immigrants came to the United States with
> Some economists have theorized that one of the reasons that men earn higher incomes than women (SEX: 1 = Male, 2 = Female) is that men work longer hours (HRS1). a. Conduct a statistical test to determine whether this contention is true. b. Are the requir
> Study after study indicate that men earn higher incomes than women (SEX: 1 = Male, 2 = Female). a. To determine the extent of the differential in 2014 estimate the difference between male and female annual incomes (RINCOME). b. What are the required cond
> The upside to working for self-employment is that there is virtually no upper limit to income. If so, we would expect self-employed individuals (WRKSLF: 1 = Self-employed, 2 = Someone else) to have higher incomes (RINCOME). a. Conduct a test to determine
> As a general rule government employees (WRKGOVT: 1 = Government, 2 = Private) have more job security than do private sector employees. Do they also have higher incomes RINCOME)? a. Conduct a test to answer the question. b. Are the required conditions sat
> Refer to Exercise 14.34. Suppose that you want to determine which of the following pairs of means differ (POLVIEWS: 1 and 2, 1 and 3, 2 and 3). a. Which technique should you use? b. Use the technique and describe your results. Data from Exercise 14.34:
> Refer to Exercise 14.39. Use Tukey’s multiple comparison method to determine which pairs differ. Data from Exercise 14.39: Television networks and their advertisers are constantly surveying viewers to determine their likes and dislikes and how much time
> a. Use the analysis of variance to determine whether there is enough evidence to conclude that there are differences in the years of education (EDUC) between the liberals, moderates, and conservatives (POLVIEWS3: 1 = Liberal, 2 = Moderate, 3 = Conservati
> Refer to Exercise 14.31. Apply Tukey’s multiple comparison method to test for differences in income for each pair of political views. Data from Exercise 14.31: What happens to Americans’ political philosophies as they grow richer? If they change we woul
> (Exercise 2.44 revisited) The associate dean of a business school was looking for ways to improve the quality of the applicants to its MBA program. Inparticular, she wanted to know whether the undergraduate degree of applicants differed among her school
> Refer to Exercise 14.30. Suppose that you want to determine whether there are differences in the amount of education between each pair of liberals: POLVIEWS: 1 = Extremely liberal, 2 = Liberal, 3 = Slightly liberal. a. Which procedure should you use? b.
> Refer to Exercise 14.29. If you wanted to determine whether the following pairs of means differ: PARTYID: 1 and 3, 1 and 5, 3 and 5, which multiple comparison method would you select? What value of a would you use? Perform the test. Data from Exercise 1
> Is it a myth that Democrats are more educated than Republicans and Independents? a. Use the analysis of variance to determine whether the years of education (EDUC) differ among Democrats, Independents, and Republicans (PARTYID3: 1 = Democrat, 2 = Indepen
> a. Use the analysis of variance to test for differences in the number of hours worked (HRS1) between races (RACE: 1 = White, 2 = Black, 3 = Other). b. Apply Tukey’s method to determine whether there are differences. c. Describe what you have discovered.
> a. Apply the analysis of variance to determine whether there is enough evidence to conclude that there are differences in income (RINCOME) between the races (RACE: 1 = White, 2 = Black, 3 = Other). b. Use Tukey’s method to determine which means differ.
> Refer to Exercise 14.27. a. Use Tukey’s multiple comparison method to determine which pairs of political parties differ. b. Use an appropriate method the compare the three Independents with the other. That is, test for the following pairs of means PARTYI
> Refer to Exercise 14.26. a. Apply Tukey’s multiple comparison method to determine which pairs of means differ. b. Use the Bonferroni adjustment test to determine whether there are differences between each of the following pairs of Independents: PARTYID:
> Refer to Exercise 14.25. a. Apply Tukey’s multiple comparison method to determine whether any means differ b. Is this result different from analysis of variance F-test? Data from Exercise 14.25: If differences in income exist, is it because higher-incom
> Refer to Exercise 14.24. Suppose that all you want to know is whether there are statistically significant differences in income between the three Independents (PARTYID: 2, 3, and 4). Perform the appropriate statistical procedure. Data from Exercise 14.2
> Refer to Exercise 14.23. a. Apply Tukey’s multiple comparison method to determine which pairs of means differ. b. Use the Bonferroni adjustment test to determine whether there are differences between each of the following pairs: PARTYID: 0 and 1, 0 and 2
> Because television audiences of newscasts tend to be older (and because older people suffer from a variety of medical ailments), pharmaceutical companies’ advertising often appears on national news on the three networks (ABC, CBS, and NBC). To determine
> Are government jobs more complex requiring more education than do private sector jobs? a. Test to determine whether there is enough evidence to conclude that government workers (WRKGOVT: 1 = Government, 2 = Private) have more education than do private se
> Another way to explain the results of Exercise 13.64 is to look at the differences in the number of hours of work. a. Is there sufficient evidence to infer that Conservatives work longer hours than Liberals (POLVIEWS3: 1 = Liberal, 3 = Conservative) (HRS
> We can attempt to explain the results in Exercise 13.63 by determining whether Conservatives are more educated than Liberals (POLVIEWS3: 1 = Liberal, 3 = Conservative). Test to determine whether Conservatives have more education than Liberals (EDUC). Wha
> As was the case with Democrats and Republicans we would expect that Conservatives would have higher incomes (POLVIEWS3: 1 = Liberal, 3 = Conservative) a. Conduct a statistical test to determine whether we can conclude that Conservatives, income exceeds t
> Is there sufficient evidence to infer that there are differences in marital status between people born in the United States and those born outside the United States (BORN: 1 = U.S., 2 = outside U.S.; MARITAL: Marital status: 1. Married, 2. Widowed, 3. Di
> Immigration has become a hot-button issue in American politics. One question that arises is: Are immigrants’ educational attainments differentfrom those born in the United States? Conduct a test to answer the question (BORN: 1 = U.S., 2 = outside U.S.; D
> Is there sufficient evidence to infer that support for capital punishment (CAPPUN: 1 = Favor, 2 = Oppose) is related to political affiliation (PARTYID3: 1 = Democrat, 2 = Republican, 3 = Independent)?
> In the last two decades, an increasing proportion of women have entered the workforce. Determine whether there is enough evidence to conclude that men and women (SEX) differ in their work status (WRKSTAT).
> The issue of gun control in the United States is one that is often debated particularly during elections. The question arises, What does the public think about the issue and does support vary from year to year? Test to determine whether there is enough e
> Are government workers more or less conservative than people who work in the private sector? Is there sufficient evidence to conclude that government workers (WRKGOVT: 1 = Government, 2 = Someone else) differ from private-sector workers in terms of their
> During the past decade, many cigarette smokers have attempted to quit. Unfortunately, nicotine is highly addictive. Smokers use a large number of different methods to help them quit. These include nicotine patches, hypnosis, and various forms of therapy.
> Do Americans who work for themselves (WRKSLF: 1 = Self-employed, 2 = Someone else) support the same political groups (PARTYID3: 1 = Democrat, 2 = Independent, 3 = Republican) as Americans who work for someone else? Conduct a statistical test to answer th
> Is it a myth that men are more conservative and women more liberal? Conduct a test to determine whether men and women (SEX: 1 = Male, 2 = Female) differ in their political views (POLVIEWS3: 1 = Liberal, 2 = Moderate, 3 = Conservative).
> Do foreign-born Americans differ from Americans born in the United States (BORN: 1 = Born in the United States, 2 = Born elsewhere) in their support of political groups (PARTYID3: 1 = Democrat, 2 = Independent, 3 = Republican)?
> An important element in the business of politics is to know who supports you and who doesn’t. Is there sufficient evidence to infer that men and women (SEX: 1 = Male, 2 = Female) differ in their support of the political groups (PARTYID3: 1 = Democrat, 2
> Which political party is more educated? Conduct a test to determine whether differences in education (EDUC) actually exist among some of the eight political categories.
> Has the amount of television American adults watch been constant over the years 2006, 2008, 2010, 2012, and 2014 or has the amount varied. Test to determine whether the number of hours of television per day (TVHOURS) changed over the 8-year span.
> Has educational levels kept uniform over the years 2006, 2008, 2010, 2012, and 2014? Conduct a test to determine whether the number of years of education (EDUC) differs in the 8-year period.
> Is it government’s responsibility to help pay for doctor and hospital bills (HELPSICK: 1 = Government should help; 2, 3, 4, 5 = People should help themselves)?
> Should government do more or less to solve country’s problems (HELPNOT: 1 = Government should do more; 2, 3, 4, 5 = Government does too much)?
> Should government improve standard of living of poor people (HELPPOOR: 1 = Government act; 2, 3, 4, 5 = People should help themselves)?
> Should government reduce income differences between rich and poor EQWLTH: 1 = Government should reduce differences; 2, 3, 4, 5, 6, 7 = No government action)?
> Do educated people work longer or shorter hours than do less-educated individuals? Conduct a test to determine whether there is enough evidence to conclude that differences exist in the number of hours per week (HRS1) between the five groups of education
> Television networks and their advertisers are constantly surveying viewers to determine their likes and dislikes and how much time adults spend watching television per day. Do the data allow us to infer that the amount of television (TVHOURS) differs by
> How does acquiring additional degrees contribute to higher incomes? Conduct a test to determine whether the degree holders (DEGREE: 0 = Left high school, 1 = High school, 2 = Junior college, 3 = Bachelor’s degree, 4 = Graduate degree) differ in income (R
> The survey asked, “Is it government’s responsibility to help pay for doctor and hospital bills (HELPSICK: 1 = Government should help; 2, 3, 4, 5 = People should help themselves)? Is there enough evidence to conclude that differences exist among some or a
> Can we infer from the data that there are differences between the seven political viewpoints in their answer to the question? “Should government do more or less to solve country’s problems (HELPNOT: 1 = Government should do more; 2, 3, 4, 5 = Government
> The survey asked, “Should government improve standard of living of poor people (HELPPOOR: 1 = Government act; 2, 3, 4, 5 = People should help themselves)?” Is there enough statistical evidence to conclude that some or all of the seven groups differ in th
> Is there enough evidence to infer that there are differences between the seven political viewpoints in their answers to the question. “Should government reduce income differences between rich and poor (EQWLTH: 1 = Government should reduce differences; 2,
> Is it true that younger Americans tend to be liberal and older Americans more conservative? To help discover the truth, start by determining whether there is enough statistical evidence to conclude that there are differences in age (AGE) among the seven
> Is it a myth that conservatives work harder than do liberals and moderates? Test to determine whether there are differences in number of hours of work per week (HRS1) among some or all of the seven political points of view.
> To determine the actual side effects, pharmaceutical companies often conduct studies that compare the side effects of their drug versus the side effects of a placebo. One such study examined the side effects of a new cold remedy. A random sample of 250 p
> What happens to Americans’ political philosophies as they grow richer? If they change we would expect differences in income (RINCOME) between the seven groups. Is there enough evidence to conclude that such differences exist?
> Are liberals, moderates, and conservatives all equally educated? Test to determine whether differences exist among the seven political views in the amount of education (EDUC).
> With government-funded health insurance in the air the next question may be particularly relevant. Is it government’s responsibility to help pay for doctor and hospital bills HELPSICK: 1 = Government should help; 2, 3, 4, 5 = People should help themselve
> The question that the survey asked is, “Should government do more or less to solve country’s problems (HELPNOT: 1 = Government should do more; 2, 3, 4, 5 = Government does too much)? Can we infer from the data that there are differences among some or all
> Is there enough statistical evidence to conclude that the eight political categories differ in their responses to this question, “Should government improve standard of living of poor people (HELPPOOR: 1 = Government act; 2, 3, 4, 5 = People should help t
> The survey asked the question, “Should government reduce income differences between rich and poor (EQWLTH: 1 = Government should reduce differences; 2, 3, 4, 5, 6, 7 = No government action)? Is there enough evidence to infer that there are differences am
> Refer to Exercise 14.24. If differences in income exist, is it because higher-income Americans work harder? Can we conclude from the data that there are differences in the hours worked (HRS1) between the eight political groups? Data from Exercise 14.24:
> Does income affect the way Americans choose which party to support? Conduct a statistical procedure to determine whether there are differences in income (RINCOME) between some or all of the eight political groups.
> Can we infer that the General Social Survey in 2014 overrepresented at least one education category (DEGREE)?
> Can we infer that the General Social Survey in 2014 overrepresented at least one category of marital status (MARITAL)?
> (Example 2.4 revisited) A major North American city has four competing newspapers: the Globe and Mail (G&M), Post, Sun, and Star. To help design advertising campaigns, the advertising managers of the newspapers need to know which segments of the newspape
> Test to determine whether there is sufficient evidence that the General Social Survey in 2014 overrepresented at least one race (RACE).
> Are Americans more deeply in debt this year compared to last year? To help answer this question a statistics practitioner randomly sampled Americans this year and last year. The sampling was conducted so that the samples were matched by the age of the he
> The fluctuations in the stock market induce some investors to sell and move their money into more stable investments. To determine the degree to which recent fluctuations affected ownership, a random sample of 170 people who confirmed that they owned som
> Refer to Exercise 14.9. Another study was conducted in the following way. Students from each of the high schools who were admitted to the business program were matched according to their high school averages. The average grades in the first year were rec
> Do medical specialists differ in the amount of time they devote to patient care? To answer this question a statistics practitioner organized a study. The numbers of hours of patient care per week were recorded for five specialists. The experimental desig
> The advertising revenues commanded by a radio station depend on the number of listeners it has. The manager of a station that plays mostly hard rock music wants to learn more about its listeners—mostly teenagers and young adults. In particular, he wants
> Exercise 14.10 described an experiment that involved comparing the completion times associated with four different income tax forms. Suppose the experiment is redone in the following way. Thirty people are asked to fill out all four forms. The completion
> A recruiter for a computer company would like to determine whether there are differences in sales ability between business, arts, and science graduates. She takes a random sample of 20 business graduates who have been working for the company for the past
> Refer to Exercise 14.14. Despite failing to show that differences in the three types of fertilizer exist, the scientist continued to believe that there were differences, and that the differences were masked by the variation between the plots of land. Acc
> In recent years, lack of confidence in the Postal Service has led many companies to send all of their correspondence by private courier. A large company is in the process of selecting one of three possible couriers to act as its sole delivery method. To
> Econetics Research Corporation, a well-known Montreal-based consulting firm, wants to test how it can influence the proportion of questionnaires returned from surveys. In the belief that the inclusion of an inducement to respond may be important, the fir
> How well do diets work? In a preliminary study, 20 people who were more than 50 pounds overweight were recruited to compare four diets. The people were matched by age. The oldest four became block 1, the next oldest four became block 2, and so on. The nu
> As an experiment to understand measurement error, a statistics professor asks four students to measure the height of the professor, a male student, and a female student. The differences (in centimeters) between the correct dimension and the ones produced
> a. Calculate SS(Total), SST, SSB, and SSE, assuming that the accompanying data were generated from a randomized block experiment. b. Calculate SS(Total), SST, and SSE, assuming that the data below were generated from a oneway (independent samples) experi
> a. Assuming that the data shown here were generated from a randomized block experiment calculate SS(Total), SST, SSB, and SSE. b. Assuming that the data below were generated from a one-way (independent samples) experiment calculate SS(Total), SST, and SS
> A randomized block experiment produced the following statistics. k = 3 b = 8 SST = 1,500 SS(Total) = 3,500 a. Test at the 5% significance level to determine whether the treatment means differ given that SSB = 500. b. Repeat Part a with SSB = 1,000. c.
> Suppose the following statistics were calculated from data gathered from a randomized block experiment with k = 4 and b = 10: SS(Total) = 1,210 SST = 275 SSB = 625 a. Can we conclude from these statistics that the treatment means differ? (Use = .01
> A randomized block experiment produced the following statistics: k = 5 b = 12 SST = 1,500 SSB = 1,000 SS(Total) = 3,500 a. Test to determine whether the treatment means differ. (Use = .01.) b. Test to determine whether the block means differ. (Use
> The following statistics were generated from a randomized block experiment with k = 3 and b = 7: SST = 100 SSB = 50 SSE = 25 a. Test to determine whether the treatment means differ. (Use = .05.) b. Test to determine whether the block means differ. (U
> Are the data in Exercise 13.18 observational or experimental? Explain. If the data are observational, describe a method of producing experimental data.
> Refer to Exercise 13.17. If the data are observational, describe another conclusion other than the one that infers that Tastee is better for babies. Data from Exercise 13.17: The president of Tastee Inc., a baby-food producer, claims that her company’s
> One of the issues that came up in a recent national election (and is likely to arise in many future elections) is how to deal with a sluggish economy. Specifically, should governments cut spending, raise taxes, inflate the economy (by printing more money
> Random sampling from two normal populations produced the following results: x1 = 412 s1 = 128 n1 = 150 x2 = 405 s2 = 54 n2 = 150 a. Can we infer at the 5% significance level that 1 is greater than 2? b. Repeat part (a) decreasing the standard deviatio
> A management scientist believes that one way of judging whether a computer came equipped with enough memory is to determine the age of the computer. In a preliminary study, random samples of computer users were asked to identify the brand of computer and
> Random sampling from two normal populations produced the following results: x1 = 63 s1 = 18 n1 = 50 x2 = 60 s2 = 7 n2 = 45 a. Estimate with 90% confidence the difference between the two population means. b. Repeat part (a) changing the sample standard
> Spam is the price we pay for being able to easily communicate by e-mail. Does spam affect everyone equally? In a preliminary study, university professors, administrators, and students were randomly sampled. Each person was asked to count the number of sp
> Many college and university students obtain summer jobs. A statistics professor wanted to determine whether students in different degree programs earn different amounts. A random sample of 5 students in the B.A., B.Sc., and B.B.A. programs were asked to
> Are Canadian public servants gaming the system by taking more sick days than do private sector workers? To answer the question Statistics Canada took a random sample of white-collar public servants and a random sample of white collar private sector worke
> Which Canadians give the most to charity? A Statistics Canada study took random samples of men and women and recorded the amount donated to charity in the previous year. Is there sufficient evidence to infer that there are differences between the two sex
