New Semester Started Get 50% OFF Study Help! --h --m --s Claim Now

Question Answers

Textbooks

Find textbooks, questions and answers

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Study Help
Tutors
AI Study Planner NEW
Sell Books

Search
Sign In
Register

study help
business
a course in statistics with r

Mind On Statistics 5th Edition Jessica M Utts, Robert F Heckard - Solutions

In a sample of 500 college students, it was found that offering discount coupons for restaurant meals substantially increased the likelihood that the students would eat at those restaurants.Explain how “extending results inappropriately” may be a problem in applying this finding to the whole
An experiment on elephants in captivity was done to find out whether breeding would occur more often when the elephants were kept together in a herd or when a male was isolated with a female. Explain how ecological validity affects the ability to generalize these results to wild elephants.
An investigator believes that a new medication will help to reduce anxiety and that a placebo will not. In a single-blind study (patients are blind to the treatment), she finds that the group taking the new medication had reduced anxiety while the placebo group did not. Explain how the experimenter
In a study on worker productivity done in 1927 in Cicero, Illinois, it was observed that productivity improved when the lighting was increased. However, it was observed that productivity also improved when the lighting was decreased.What term is used to describe the fact that productivity increased
A new medication is observed to cause a weight loss in women but a weight gain in men. Identify what the response variable, explanatory variable, and interacting variable are in this situation.
Researchers have found that women who take oral contraceptives(birth control pills) are at higher risk of having a heart attack or stroke and that the risk is substantially higher if a woman smokes. In investigating the relationship between taking oral contraceptives (the explanatory variable)and
For each of the following, explain whether the study summary describes an interacting variable or a confounding variable.a. It is found that the difference between the mean grade point averages of male and female students is greater for fraternity and sorority members than for students who are not
This is also Exercise 1.25. An article in Science magazine(Service, 1994) discussed a study comparing the health of 6000 vegetarians and a similar number of their friends and relatives who were not vegetarians. The vegetarians had a 28% lower death rate from heart attacks and a 39% lower death rate
This is also Exercise 1.38. A headline in a major newspaper read, “Breast-Fed Youth Found to Do Better in School.”a. Do you think this statement was based on an observational study or a randomized experiment? Explain.b. Given your answer in part (a), which of these two alternative headlines do
Explain why it is preferable, whenever possible, to conduct a randomized experiment rather than an observational study.
times as likely to come down with cold symptoms and signs of infection compared to those with six or more contacts.”a. Explain why this is an observational study, not a randomized experiment.b. What were the explanatory and response variables of interest to the researchers?c. The researchers in
Reuters (June 24, 1997) reported on a study published in the Journal of the American Medical Association (1997, vol. 277, pp. 1940–1944) in which researchers recruited 276 volunteers(aged 18 to 55) and used nose drops to infect them with a cold virus. The volunteers were then quarantined and
A story at ABCNews.com (“Pet Contact” by Rita Rubin, March 17, 1998) reported that Karen Allen, a researcher at the University of Buffalo, found that couples who own cats or dogs have more satisfying marriages and are less stressed out than those who don’t own pets. Pet owners also have more
Find an example of an observational study in the news.Determine whether or not it was a case–control study and whether it was prospective or retrospective. Specify the explanatory and response variables, and explain whether confounding variables were likely to be a major problem in interpreting
A study will be done to determine the relationship, if any, between where a college student lives (on-campus or offcampus)and grade point average. Would it be better to use a randomized experiment or an observational study? Explain.
Suppose researchers were interested in determining the relationship, if any, between the use of cell phones and the incidence of brain cancer. Would it be better to use a randomized experiment, a case–control study, or an observational study that did not use cases and controls? Explain.
A medical researcher wants to know how lifetime sun exposure affects the risk of skin cancer for persons over 50 years old. Describe how data might be collected for a retrospective case–control study.General Section Exercises
Students who had meningitis were matched with students without meningitis using sex, undergraduate (or graduate)status, and college. The students’ recent activities were examined to discover risk factors for meningitis. Explain whether each of the following terms applies to this observational
Students whose undergraduate major was economics were followed for 10 years after graduation to study the number of different jobs they took. Explain whether each of the following terms applies to this observational study.a. Prospective study.b. Retrospective study.c. Case–control study.
Suppose you want to know whether men or women spend more time talking on a cell phone during a week’s time.a. Describe how you would collect the data in a retrospective observational study.b. Describe how you would collect the data in a prospective observational study.c. Refer to parts (a) and
A teacher wants to determine how class attendance during the term affects grades on the final exam.a. Describe how the data would be collected in a prospective observational study.b. Describe how the data would be collected in a retrospective observational study.c. Refer to parts (a) and (b). Give
Echinacea is an herb that may help to prevent colds and flu. Explain how researchers could conduct a double-blind, double-dummy experiment to compare echinacea tea with chewable vitamin C pills for effectiveness in preventing colds.Section 6.3 Skillbuilder Exercises
Refer to Exercise 6.27. In each case, explain whether a control group was used and whether a placebo treatment was used.
Refer to Exercise 6.27. In each case, explain whether the experiment was a matched-pair design, a block design, or neither.
Refer to Exercise 6.27. In each case, designate the explanatory variable and the response variable.
A fast-food chain sells its burgers alone or as part of a “value meal” that includes fries and a drink. They know that some customers are health-conscious. They want to do an experiment to determine whether the proportion of customers choosing the meal would increase if they offered baby
Explain whether each of the following experiments was single-blind, double-blind, or neither.a. An electric company wanted to know whether residential customers would use less electricity during peak hours if they were charged more during those hours. One hundred customers were randomly selected to
(p. 201), “Quitting Smoking with Nicotine Patches,” which used a completely randomized design. Explain how the experiment could have been done by using a randomized block design instead.
(p. 199) for guidance, explain how you could use statistical software such as Minitab to randomly assign participants to treatments. 6.26 Refer to Case Study
One hundred volunteers agree to participate in an experiment.There are four treatments, each of which will be assigned to 25 participants. Using Example
A school district has 20 elementary schools, and each school has 12 classes that can be used for a study.a. Using schools as blocks, describe a randomized block design to compare three teaching methods.b. Explain why schools should be used as blocks.
Twenty volunteers aged 40 to 65 years old will participate in an experiment to compare two methods of memorizing information.The age variation in the participants concerns the researchers because memorization skills decrease with age.a. Describe how the study could be done using a matchedpair
Researchers want to design a study to compare topical cream (applied to the skin) and a drug taken in capsule form for the treatment of a certain type of skin rash. Sixty volunteers who have the rash agree to participate in the study.a. If each volunteer is given only one treatment, can the study
Twenty grocery stores will participate in an experiment to compare the effectiveness of two methods for displaying a product. The response variable will be the number of items of the product sold during a 1-week period.a. Describe a completely randomized design for this experiment.b. Describe a
(p. 203)illustrating the steps of the study.General Section Exercises
(p. 197)illustrating the steps of the study.b. For the randomized block design described for that experiment, draw a figure similar to Figure
An experiment to determine the effect of caffeine on swimming speed is described on page 204.a. For the completely randomized design described for that experiment, draw a figure similar to Figure
Twenty students agreed to participate in a study on colds.Ten were randomly assigned to receive vitamin C, and the remaining 10 received a tablet that looked and tasted like vitamin C but in fact contained only sugar and flavoring. The students did not know whether they were taking vitamin C or
Two weight-training regimens designed to improve arm strength will be compared. The response variable will be the improvement in arm strength at the end of six weeks of training. Forty individuals—20 males and 20 females—will participate in the study.a. Describe how a completely randomized
Suppose that we want to determine whether people who want to lose weight would lose more in three months by dieting or by exercising. Sixty people have volunteered to participate.Briefly describe how a randomized experiment would be done in this situation.
(p. 197) illustrating the steps of the study.c. Describe the replication in this study.
An experiment will be done to determine whether college students learn information better when listening to rap music, when listening to classical music, or when not listening to music. In the study, each participant will read a chapter from a history textbook and then take a test about the
(p. 196), illustrating the steps in this study. 6.15Case Study 1.5 in Chapter 1 was about the association between blood pressure and frequency of participating in religious activities. Why was this study conducted as an observational study instead of an experiment?Section 6.2 Skillbuilder Exercises
A news article on the Reuters Health website, December 18, 1998, reported that:A study of over 1200 people over age 65 showed that the“owls”—those who go to sleep after 11 p.m. and rise after 8 a.m.—tend to be as healthy and intelligent as “larks”—those who go to bed before 11 p.m.
A news article by Reuters on October 6, 1998, reported:In a new study, Dr. Matti Uhari and colleagues at the University of Oulu in Finland randomly gave 857 healthy children in daycare centers xylitol in syrup, gum, or a lozenge form, or a placebo gum or syrup in five doses per day for 3 months.
For the research scenarios in parts (a) and (b), explain whether a randomized experiment could be used.a. To compare two programs to reduce the number of commuters who drive to work: providing discount coupons for the bus, or providing shuttle service for people who need to run errands during the
For the research scenarios in parts (a) and (b), explain whether a randomized experiment could be used.a. To study the relationship between long-term practice of meditation and blood pressure.b. To determine whether a special training program improves scores on a standard college admissions test.c.
This is also Exercise 1.14. For each of the studies described, explain whether the study was an observational study or a randomized experiment.a. A group of 100 students was randomly divided, with 50 assigned to receive vitamin C and the remaining 50 to receive a placebo, to determine whether
Specify what an individual unit is in each of the following studies. Then specify what two variables were measured on each unit.a. A study finds that college students who often procrastinate tend to be sick more often than students who do not procrastinate.b. A study finds that sport utility
Remember that a confounding variable affects the response variable and is related to the explanatory variable. For each of the following situations, explain how the given confounding variable meets these criteria.a. Response variable 5 Child’s IQ at age 10; explanatory variable 5 whether mother
This is also Exercise 1.13. For each of the examples given here, decide whether the study was an observational study or a randomized experiment.a. A group of students who were enrolled in an introductory statistics course were randomly assigned to take an online course or to take a traditional
This is also Exercise 1.16. Suppose that an observational study showed that students who got at least seven hours of sleep performed better on exams than students who didn’t.Which of the following are possible confounding variables, and which are not? Explain why in each case.a. Number of courses
Remember that a confounding variable affects the response variable and is related to the explanatory variable. For each of the following situations, explain how the given confounding variable meets these criteria.a. Response variable 5 Math skills of children aged 6 to 12 years old; explanatory
Suppose that a statistics teacher wants to know whether the number of hours students spend studying in a group affects the final course grade. In each part, explain whether the research method described is a randomized experiment or an observational study.a. Each student keeps a log of the hours he
Refer to Exercise 6.1. In each part, specify the explanatory variable and the response variable.
In each part, identify the response variable and the explanatory variable in the relationship between the two given variables.a. Daughter’s height and mother’s height.b. Age and weight for children between the ages of 3 and 10 years old.c. Opinion about the death penalty for persons convicted
In each situation, indicate whether you think an observational study or a randomized experiment would be used.Explain why in each case.a. A teacher wants to compare the grade point averages of female students who are in sororities to the grade point averages of female students who are not in
5.112 One question asked was as follows: “The term affirmative action has different meanings to different people. Please tell me which statement best describes what you mean by the term: First, affirmative action means granting preferences to women and certain racial and ethnic groups.Second,
5.111 Refer to Exercise 5.110. Of the 166 arts and humanities faculty members, 66% favored the policy, while of the 229 engineering, mathematical, and physical sciences faculty, 38%favored it.a. Find the conservative margin of error for the arts and humanities faculty, and use it to compute an
5.110 One of the questions asked was, “Do you favor or oppose using race, religion, sex, color, ethnicity, or national origin as a criterion for admission to the University of California?” Of the 804 male respondents, 47% said “Favor,” and of the 197 female respondents, 73% said
5.109 The article also reported that “among GOP voters, 39 percent give Feinstein high marks.” Would the margin of error accompanying this result be larger, smaller, or the same as the margin of error for the entire sample? Explain.Exercises 5.110 to 5.112 refer to a survey of University of
5.108 The report stated that the margin of error was 3.8 percentage points. This value is based on the 642 voters who were considered likely to vote and uses the precise formula you will learn in Chapter 10.a. Compute the conservative margin of error for this poll based on those likely to vote, and
5.107 The text of the article said that the 750 adults surveyed were actually 750 registered voters. Based on the information about who was surveyed, if the poll results are to be used to predict the proportion of voters who were likely to vote for Senator Feinstein in November, should the results
5.106 Read the headline that accompanied the article, which stated that ratings were “up” for both senators. For the June 2000 poll, 57% approved of Feinstein’s performance, compared with 56% and 53%, respectively, for similar polls taken in February 2000 and October 1999. Presumably, the
5.106 to 5.109 are based on a report of a Field poll printed in the Sacramento Bee on July 7, 2000 (Dan Smith, p. A4), with the headline, “Ratings Up for Boxer, Feinstein in New Poll.” The results were reported with a graphical display containing the information that “results are based on a
5.105 Find an example of a poll that would be considered unscientific because it does not represent a population other than those who responded. Write a few paragraphs describing how the poll was conducted, what was asked, and the results. Explain which of the problems discussed in Sections 5.5 and
5.104 Find an example of a poll conducted by a reputable scientific polling organization. Write a few paragraphs describing how the poll was conducted, what was asked, and the results.Explain whether or not any of the problems discussed in Sections 5.5 and 5.6 were likely to have biased the results
5.103 Suppose an (unscrupulous!) organization wanted to conduct a survey in which the results supported its position that drinking coffee in public should be illegal except in designated coffee bars. Explain how the organization could use each of the following sources of bias to help produce the
5.102 An ABCNews.com poll conducted by TNS Intersearch June 13–17, 2001, posed the following question to a random sample of n 5 1024 adult Americans: “Scientists can change the genes in some food crops and farm animals to make them grow faster or bigger and be more resistant to bugs, weeds and
5.101 Refer to the survey described in Example 5.9, “Which Scientists Trashed the Public?” Explain which type of bias(selection bias, nonparticipation bias, or biased response)was the most problematic in that survey.
5.100 For this exercise, use the data in Case Study 1.1 (p. 2) or in the file pennstate1 on the companion website.a. Select a random sample of ten males and a random sample of ten females, and write down their answers to the question “What’s the fastest you’ve ever driven a car?”b. Compare
5.99 Refer to Exercises 5.96 and 5.97. Suppose that a local newspaper conducted a survey during the next week, based on randomdigit dialing of 1400 residents of the area, and found that 20% of them reported having seen a UFO on the evening in question.a. What is the margin of error for the
5.98 Refer to the Literary Digest poll in Case Study 5.1. Discuss the extent to which each of the following types of bias played a role in producing the disastrous results, if at all.a. Selection bias.b. Nonparticipation bias.c. Response bias.
5.97 Refer to Exercise 5.96. Acknowledging that some bias is inevitable when information is required on such short notice, which of the four methods would you recommend that the television station use to get the information it desires?Explain.
5.96 One evening around 6 P.M., authorities in a major metropolitan area received hundreds of phone calls from people reporting that they had just seen an unidentified flying object(UFO). A local television station would like to report the story on their 10 P.M. news and wants to include an
5.95 An article in the Sacramento Bee was headlined, “Drop found in risky behavior among teens over last decade”(June 7, 2000, p. A6; reprinted from the Los Angeles Times).The article reported that “the findings show that for the general population [not a specific ethnic group], the share of
5.94 A large medical professional organization with membership consisting of doctors, nurses, and other medical employees wanted to know how its members felt about HMOs (health maintenance organizations). Name the type of sampling plan they used in each of the following scenarios:a. They randomly
5.93 Refer to Exercise 5.92.a. What is the population of interest to the faculty senate?b. What is the sampling frame?c. What is the sample?d. Is the sample representative of the population of interest?Explain.
5.92 The faculty senate at a large university wanted to know what proportion of the students thought that a foreign language should be required for everyone. The statistics department offered to cooperate in conducting a survey, and a simple random sample of 500 students was selected from all
5.91 Suppose that a survey reported that 55% of respondents favored gun control, with a margin of error of 6 3 percentage points.a. What was the approximate size of the sample?b. What is an approximate 95% confidence interval for the percentage of the corresponding population who favor gun
5.90 Refer to Exercise 5.89, in which a survey question was, “Do you favor or oppose scientific experimentation on the cloning of human beings?” Suppose an agency that advocated cloning of human beings wanted to conduct a survey that would show support for their cause. Explain how it might use
5.89 A Pew Research Center for the People & the Press and Pew Forum on Religion & Public Life survey conducted by Princeton Survey Research Associates between February 25 and March 10, 2002, asked a random sample of n 5 2002 adult Americans, “Do you favor or oppose scientific experimentation on
5.88 Suppose you wanted to estimate the proportion of adults who write with their left hands and decide to watch a sample of n people signing credit card receipts at a mall.a. Do you think this sample would be representative for the question of interest? Explain.b. Assuming that the sample was
5.87 Refer to Example 5.17, “Politics Is All in the Wording.”Explain which one of the “Difficulties and Disasters” listed in Section 5.5 is illustrated by this example.
5.86 Refer to Example 5.17, “Politics Is All in the Wording.”Explain which one of the seven “Possible Sources of Response Bias in Surveys” is illustrated by this example.
5.85 Suppose a community group wants to convince city officials to put more trash containers on the city streets. They decide to conduct a survey, but rather than produce a scientifically valid result, they want their results to show that as many citizens as possible want additional trash
5.84 This is also Exercise 1.36. The CNN website sometimes has a small box called “Quick vote” that contains a question about an interesting topic in the news that day. For example, one question in February 2010 asked, “Should the U.S. military let gays and lesbians serve openly?” Visitors
5.83 This is also Exercise 1.7. A CBS News poll taken in December 2009 asked a random sample of 1048 adults in the United States, “In general, do you think the education most children are getting today in public schools is better, is about the same, or is worse than the education you
5.82 Refer to Exercise 5.81. Another question that was asked in the poll was “Do you consider yourself a fan of Elvis Presley, or not?” The responses were almost equally split, with 49% saying“yes” and 51% saying “no” (http://www.pollingreport.com/music.htm, September 29, 2002). Do you
5.81 Rock singer Elvis Presley died on August 16, 1977, and his life received substantial publicity as the 25th anniversary of his death approached on August 16, 2002. On August 7–11, 2002, an ABC News poll asked a random sample of n 5 1023 adult Americans, “Who do you think is the greatest
5.80 An advertiser of a certain brand of aspirin (let’s call it Brand B) claims that it is the preferred painkiller for headaches, on the basis of the results of a survey of headache sufferers. But further investigation reveals that the choices given to respondents were Tylenol, ExtraStrength
5.79 An NBC News/Wall Street Journal poll conducted at the end of the 20th century (September 9–12, 1999) asked a random sample of n 5 1010 adult Americans, “Which one of the following do you consider to be the best American movie of the 20th century?” The choices given and the percentages
5.78 Explain which of three methods—a doortodoor interview, a telephone interview, or a mail survey—would be least likely to suffer from each of the following problems:a. Bias due to desire to please the interviewer.b. Volunteer response.c. Bias due to perceived lack of confidentiality.
5.77 Explain which of three methods—a doortodoor interview, a telephone interview, or a mail survey—would be most likely to suffer from each of the following problems:a. Bias due to desire to please the interviewer.b. Volunteer response.c. Bias due to perceived lack of confidentiality.
5.76 A Gallup poll that was released on July 9, 1999, included a series of questions about possible religious activities in public schools. The poll was based on telephone interviews with a randomly selected sample of 1016 U.S. adults conducted June 25–27, 1999.The questions, asked in random
5.75 Give an example of two survey questions for which you think the results would be substantially different depending on which order they were asked.
5.74 An Internet poll sponsored by a site called About.com asked Internet users to pick one of two choices in response to the question, “Should jurors opposed to gun control laws refuse to convict defendants even if they have clearly broken gun laws?” The two choices and the number and
5.73 Refer to Example 5.16, “When Will Adolescent Males Report Risky Behavior?” Explain which two of the seven “Possible Sources of Response Bias in Surveys” are illustrated by this example.
5.72 In presidential election years in the United States, a Gallup poll is conducted in which the first survey question asks which presidential candidate the voter prefers. Subsequent questions concern other political, social, and election issues.Explain why this question order might be the best
5.71 Medical tests, such as those for detecting HIV, sometimes concern such sensitive information that people do not want to give their names when they take the test. In some instances, a person taking such a medical test is given a number or code that he or she can use later to learn the test

Showing 1100 - 1200 of 2302

First
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Last

Step by Step Answers

Services

Sitemap
Fun
Definitions
Become Tutor
Used Textbooks
Study Help Categories
Recent Questions
Expert Questions
Campus Wear
Sell Your Books

Company Info

Security
Copyrights
Privacy Policy
Terms & Conditions
SolutionInn Fee
Scholarship
Online Quiz
Give Feedback, Get Rewards

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Student Discount
Campus Ambassador

Secure Payment

Download Our App

© 2026 SolutionInn. All Rights Reserved