Chapter 12 Review Problems

Chapter 12 Review Problems - Chapter 12 Sample Surveys...

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Unformatted text preview: Chapter 12 Sample Surveys (Review) Name MGLTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the questions Answer the question. 1) A magazine publisher mails a survey to every subscriber asking about the quality of its 1) subscription service. The total number of subscribers represents What? A) The population B) A census C) The population parameter of interest D) The sampling frame E) Involuntary sampling 2) A magazine publisher mails a survey to every subscriber asking about the timeliness of its 2) subscription service. The publisher finds that only4% of the subscribers responded. This 4% represents what? A) A census 3) The sampie C) The sampiing method 1)) The population parameter of interest E) The sampling frame 3) A magazine publisher will mail a survey to 14% of its subscribers that Wili be chosen at random. 3) The survey asks about the quality of its subscription service. All of the subscribers, who have an equal and random chance to be chosen for this survey, represent what? A) The population parameter of interest- B) A census C) The population D) The sampling frame E) The sampling method 4) A computer network manager wants to test the reliability of some new and expensive fiber—optic 4) Ethernet cables that the computer department just received. The computer department received8 boxes containing 30 cables each. The manager does not have the time to test every cable in each box. The manager will choose one box at random and test6 cables chosen randomly Within that box. lNhat is the population? A) 240 cables 8) The 8 boxes C) The proportion of reliable cables D) The one box that was chosen at random from the 8 boxes E) The 6 cables chosen randomly for testing 5) A computer network manager wants to test the reliability of some new and expensive fiberwoptic 5) Ethernet cables that the computer department just received. The computer department receivele boxes containing 30 cables each. The manager does not have the time to test every cable in each box. The manager will choose one box at random and testé cables chosen randomly within that box. What is the sampling frame? A) 300 cables 13) The 6 cables chosen for testing C) The proportion of reliable cables D) The one box that was chosen at random from the 10 boxes E) The 10 boxes 6) A computer network manager wants to test the reliability of some new and very expensive 6) fiber—optic Ethernet cables that the computer department just received. The computer department received 9 boxes containing 50 cables each. The manager does not have the time to test every cable in each box, so the manager assigns a subordinate to do a census. How many cables will be sampled if the subordinate does a census? A) It will depend on the sampling of cables and the sampling of boxes (the sampling frame). B) 50 cables C) 450 cables D) 10 cables E) 9 cables 7) Mr. Smith works at a computer consultant company that provides technical information to 7) computer departments of various manufacturing companies. Mr. Smith is alarmed at the number of spyware programs on the internet. Mr. Smith attempts to call every one of his clients only to ask (yes or no) if they have had any known problems with spyware infections on their computers or network. With regards to Mr. Smith's attempts to contact his clients for information about infections, What is the population? A) The total number of infections of spyware on Mr. Smith's clients' computers B) The total number of computers at all of Mr. Smith's clients C) 'Ihe total number of clients that Mr. Smith has D) Only the number of computers infected with spyware that Mr. Smith is informed oi E) Only the total number of clients that Mr. Smith successfully contacts 8) Jennifer is a quality control inspector for a well—known computer modem manufacturer. Iennifer 8) oversees five assembly lines, each assembly line produces the same number of modems per day. lennifer randomly selects one assembly line each morning and performs further sampling and quality control procedures on that assembly line's modems for the rest of the day. This morning, Jennifer randomly selected the modems of assembly line #5 for quality control inspection. Futhermore, Iennifer will then perform systematic sampling on that aSsembly line's modems. What has been excluded from being in the sampling frame today? A) The modems of assembly lines #1, 2, 3, and 4 B) An unbiased sample for assembly line #5 C) A sampling method for assembly line #5 D) Some of the modems of assembly line #5 E) Nothing has been excluded from the sampling frame. SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. For the given report about statistical studies, identify the following items (if possible): population, population parameter of interest, sampiing frame, sample, sampling method (include whether or not randomization was employed), any potential sources of bias you can detect and any probiems you see in generalizing to the population of interest. 9) A question posted on the internet by a well known newspaper's website asked visitors to 9) say Whether they thought the legal drinking age should be lowered to 18 for all 50 states. 10) Staff members for a local alderman go to one of the city's election polling places in his 10) district and interview all the residents they can find. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Provide an appropriate response. 11) An education researcher randomly selects 38 schools from one school district and interviews all the 11) teachers at each of the 38 schools. Identify the type of sampling used in this example. A) Systematic sampling B) Voluntary response sampling C) Stratified sampling ‘0) Attempted census E) Cluster sampling 12) At the local college a survey was being done on whether or not the students liked the cafeteria food 12) The survey was located in the college newspaper and was to be filled out and sent to the editing office. Identify the type of sampling used in this example. A) Stratified sampling B) Systematic sampling C) Voluntary response sampling D) Attempted census E) Cluster sampling 13) Before premiering a blockbuster movie at a theater, test screenings are done beforehand. A small 13) number of selected theaters are chosen geographically throughout the country. Each theater chosen is supposed to be representative of theatergoers in that area. Everyone is interviewed when the movie is over. Identify the type of sampling used in this example. A) Stratified sampling B) Cluster sampling C) Multistage sampling [3) Attempted census E) Voluntary response sampling 14) A newly—premiered play just ended that evening at a local theater. Theater management briefly 14) interviews every fifth person leaving the theater to see if that person will recommend the play at that theater to other people. Identify the type of sampling used in this example. A) Voluntary response sampling B) Stratified sampling C) Cluster sampling D) Systematic sampling E) Convenience sampling 15) A mega—discount chain store just opened a new clothing store in town emphasizing mainly 15) women’s clothing. Before opening, management had to decide whether to only carry either men's, women’s, boys‘, girls', or infants' clothing. After performing representative sampling of potential customers from each of these groups, it was decided to carry only women's clothing. Identify the type of sampling used in this example. A) Multistage sampling B) Cluster sampling C) Convenience sampling D) Stratified sampling E) Systematic sampling 16) Each person in a simple random sample of 2,000 received a Survey, and 317 people returned their 16) survey. How couid nonresponse cause the results of the survey to be biased? A) Those who did respond may differ in some important way from those who did not respond. B) Those who did not respond represent a stratum, changing the simple random sample into a a stratified random sample. C) Those who did not respond reduced the sample size, and small samples have more bias than large samples. D) Those who did not respond caused a violation of the assumption of independence. E) Theses who did not respond were indistinguishable from those who did not receive the survey. Identify the bias. 17) Inside the boxes of a new brand of cereal, is a short survey that can be maiied hack for free to the 17) manufacturer. The survey asks the consumer if he or she likes the cereal or not. What, if any, will be the most noticeable bias for this survey? A) Undercoverage of the population B) Response bias C) Nonresponse bias D) Voluntary response bias E) There does not seem to be any bias. 18) A newspaper reporter randomly sampled households by telephone during various times of the 18) day. The peopie sampled are within the area of the newspaper‘s distribution. The newspaper reporter asked, "Are you patriotic in a time of war or armed cenflict?" What, if any, will be the most noticeable bias for this survey? A) Response bias B) Voiuntary response bias C) Nonresponse bias D) Undercoverage of the population E) There does not seem to be any bias. 19) A newspaper conducted a random telephone survey during the day regarding the percentage 01 19) stay—at—home moms and dads in the typical household. What, if any, will be the most noticeable bias for this survey? A) Nonresponse bias 8) Response bias C) Undercoverage of the population D) Voluntary response bias E) There does not seem to be any bias. 20) A popular soft drink company distributes written surveys with its product that a customer can fill 20) out and mailed in or the survey can be filled out electronically on the intemet. What, if any, will be the most noticeable bias? A) Nonresponse bias B) Voluntary response bias C) Response bias D) Undercoverage of the population E) There does not seem to be any bias. 21) Management at a post office is curious about its services in one particular zip code area. Every 21) address within that zip code, including business and residential, is mailed a survey inquiring about the post office‘s quality of service. The post office does receive a respectable 19% response rate to the survey. What, if any, is the most noticeable bias for this survey? A) Nonresponse bias B) Response bias C) Undercoverage of the population D) Voluntary response bias E) There does not seem to be any bias. 2.2) Under which of the foiiowing conditions is it preferable to use stratified random sampling rather 22) than simple random sampling? A) The population can be divided into a small number of strata so that each stratum contains a large number of individuals. B) The population can be divided into strata of equal sizes so that each individual in the population still has the same chance of being selected. C) The population can be divided into strata so that the individuals in each stratum are as much alike as possible. D) The population can be divided into large number of strata so that each stratum contains only a few individuals. E) The population can be divided into strata so that the individuals in each stratum are as different as possible. Answer the question. 23) The human resources department of a large, well—known telecommunications firm would like to 23) know the job satisfaction of the employees working at its company. The HR department's goal is to have every employee participate in this survey. For this scenario, what sampling method best fits HR's goal? A) Attempted census B) Stratified sampling C) Simple random sampling D) Systematic sampling E) Convenience sampling 24) The human resources department of a large, well—known telecommunications firm would like to 24) know the job satisfaction of the employees working at its company, but the HR department is restricted by company policy to use only email to distribute and collect any type of employee questionnaire or survey. What sampling method is HR being forced to rely upon? A) Convenience sampling B) Stratified sampling C) Voluntary response sampling D) Cluster sampling E) Attempted census 25) The human resources department of a large, well—known telecommunications firm is behind 25) schedule in sampling the job satisfaction of the company's employees. In an effort to catchup, the HR manager quickly goes down an alphabetical list of employees and e—mails a survey to every tenth employee. An neutral third party collects all surveys and ensures all of the selected employees respond to the survey. What sampling method best describes what the HR manager is doing? A) Voluntary response sampling B) Systematic sampling C) Convenience sampling D) Cluster sampling E) Stratified sampling 26) The human resources manager of a large, well—known telecommunications firm is genuinely concerned about the wellwbeing of the company's employees. This HR manager will e—mail everyone within the company asking for suggestions in improving the health of employees working there. The manager will list specific problems that may affect an employee, including weight, smoking, and stress. For this scenario, what sampling method is being used? A) Stratified sampling B) Attempted census C) Cluster sampling D) Multistage sampling E) Voluntary response sampling 27) Geologists have an interest in the structure and the history of the earth. A geologist can go back it time by drilling deep into the ground, retrieving a core sample, estimating the ages of the various layers, and examining the compOsition. A timeline can be built of the entire area from where the core sample was drilled. A geologist may retrieve several core samples to confirm the history of the earth's structure in that sampled area. Mountains, lakes, and unstable ground can easily impede a simple random sampling of a desired geographical area, therefore what is the most realistic sampling method that represents flie actual drillings, comparisons, and scientific examinations of several core samples within the same geographical area? A) Systematic sampling B) Multistage sampling C) Stratified sampling D) Convenience sampling E) Cluster sampling SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Provide an appropriate response. 28) Describe the steps involved when using stratified random sampling. What are the 28) advantages of this sampling method? 29) A researcher wishes to assess the working conditions of farm workers at farms in his 29) district. There are 37 farms in the district which are widely scattered geographically. The researcher wishes to interview at least 300 farm workers. Describe a method for selecting a sample which involves cluster sampling. Each farm employs approximately 50 workers. 30) The residents of one town are classified by a social scientist as follows. 30) Lower income: 1738 Middle income: 5056 Upper income: 1106 The scientist wishes to pick a sample of 200 of the residents for a study. Describe a method for selecting the sample which involves stratified sampling with proportional allocation. 26) 27) MULTI?LE CHOICE. Choose the one alternative that best completes the statement or answers the question 31) A company sponsoring a new internet search engine wants to collect data on the ease of using it. Which is the best way to collect the data? A) sample survey B) census C) simulation D) experiment E) observational study 32) Suppose your local school district decides to randomly test high school students for attention deficit disorder (ADD). There are three high schools in the district, each with grades 9«12. The schOol board pools all of the students together and randomiy samples 250 students. Is this a simple random sampie? A) No, because we can't guarantee that there are students from each grade in the sampie. B) Yes, because each student is equaiiy likely to be chosen. C) No, because we can‘t guarantee that there are students from each school in the sample. D) Yes, because they could have chosen any 250 students from throughout the district. E) Yes, because the students were chosen at random. SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 33) Military funding A college group is hivestigating student opinions about funding of the military. They phone a random sample of students at the college, asking each person one of these questions (randomly chosen): 33) A: "Do you think that funding of the military should be increased so that the United States can better protect its citizens?" 13: "Do you think that funding of the military should be increased?" Which question do you expect will elicit greater support for increased military funding? Explain. What kind of bias is this? 31) 32) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 34) Hoping to get information that would ailow them to negotiate new rates with their advertisersi 34) Natural Health magazine phoned a random sample of 600 subscribers. 64% of those poiled said they use nutritional supplements. Which is true? I. The population of interest is the people who read this magazine. II. "64%" is not a statistic; it's the parameter of interest. III. This sampling design should provide the company with a reasonany accurate estimate of the percentage of all subscribers who use supplements. A) I and III only B) I only C) II and III only D) I and II only E) I, II, and III 35) Which statement about bias is true? 35) I. Bias Iesuits from random variation and WiII always be present. If. Bias results from a sampling method likely to produce samples that do not represent the population. III. Bias is usually reduced when sample size is Iarger. A) III only E) II only C) I only I3) I and III only E) II and III onIy 36) If we wish to compare the average PSAT scores of boys and girls taking AP Statistics at this high 36) school, which would be the best way to gather these data? A) observational study B) experiment C) stratified sample D) census E) SR8 10 37) Which is true about sampling? 37) I. An attempt to take a census will always result in less bias than sampling. ll. Sampling error is usually reduced when the sample size is larger. HI. Sampling error is the result of random variations and is always present. A) I only 3) II and III C) I, II, and III D) III only E) II only SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 38) The City Council decides to conduct a telephone poll. Pollsters ask a carefully chosen 38) random sample of adults this question: "Do you favor the construction of a new prison to éeal with the high level of violent crirne in our State?" In what way might the proportion of "Yes" answers fail to accurately reflect true public opinion? Explain briefly. What kind of bias is this? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Adminstrators of the fire department are concerned about the possibility of implementing a new property tax to raise moneys needed to replace old equipment. They decide to check on public opinion by having a random sample of the city‘s population. Provide an appropriate response. 39) Each property owner has a 5mdigit ID number. Use a random number table to choose forty 39) numbers. Identify this sampling strategy. A) cluster B) convenience C) stratified D) simple E) systematic 40) Randomly select a housing classification (say, apartments) and survey all the people who live in 40) that property classification. Identify this sampling strategy. A) stratified B) convenience C) systematic D) simple E) cluster SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 41) Briefly explain why sampling an entire housing classification might be biased. Be sure to tl1) name the kind(s) of bias you describe. 11 42) Name and briefly describe the kind of bias that might be present if the administration 42) decides that instead of subjectirtg people to a random sample they'il just ask people who are Willing to be taxed to sign a petition. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question A member of the City Council has proposed a resolution opposing construction of a new state prison there. The council members decide they want to assess public opinion before they vote on this resolution. Identify the method that is proposed to sample local residents to determine the level of public support for the resolution. 43) Have each council member survey 50 friends, neighbors, or co—workers. 43) A) voluntary response B) judgment C) simple (SR8) D) stratified E) convenience 44) Go to a downtown street corner, a grocery store, and a shopping mall; interview 100 typicai 44) shoppers at each location. A) cluster B) voluntary response C) judgment D) simple (SR8) E) convenience 45) Call every 500th person in the phone book. 45) A) simple (SR8) B) cluster C) stratified D) convenience E) systematic 46) Randomiy select several city blocks; interview all the adults living on each block. 46) A) systematic B) simple (SR8) C) cluster D) stratified E) judgment 12 Answer Key Testname: CHAPTER 12 SAMPLE SURVEYS (REVIEW) 1) A 2) B 3) D 1i) A S) D 6) C 7) C 8) A - 9) Population—U5. adults Parameterwl’roportion who feel the legal druiking age should be lowered to 18. Sampling Frame—None given; potentially all people with access to the website. Sample—Those visiting the website who responded Method—Voluntary response (no randomization employed) Bias~Volnntary response sample. Those who visit the website and respond may be predisposed to a particular answer. 10) Population~Registered voters in the local alderman‘s district. Parameter-Not clear/Percentage of voters favoring various issues? Sampling Frame-«All district residents. Sample—Cluster sample; one of the city's election polling places Method—Convenience sample within each cluster Biasd’arametefis) of interest not Clear. Sampling within clusters is not random and may bias results. 11) E 12) C 13) B 14) D 15) D 16) A 17) D 18) A 19) A 20) B 21) D 22) C 23) A 24) C 25) B 26) E 27) E 28) Answers will vary. Possible answer: The population is first divided into subpopulations (strata). From each stratum, a simple random sample is obtained whose size is proportional to the size of the stratum. The advantage of this method is that it ensures that no stratum is missed. 29) Answers will vary. Possible answer: Obtain a simple random sample of the farms as follows: Number the farms 1 to 37. Use a randorn number table to obtain a list of six random numbers between 1 and 37. Select the farms corresponding to those six numbers and interview all workers at each of the six farms. 30) Answers will vary. Possible answer: The scientist should pick a simple random sample of44 from the lower income stratum, a simple random sample of 128 from the middle income stratum, and a simple random sample of 28 from the upper income stratum“ 31) A 32) o 13 Answer Key Testname: CHAPTER 12 SAMPLE SURVEYS (REVIEW) 33) The first question will elicit greater support for increased military funding. The wording of the question appeals to the feelings of safety of the respondent. The second question does not do this— it is more neutral and wiil elicit less response. This is a form of response bias. 34) A 35) B 36) D 37) B 38) Response bias: the wording will induce people to answer "yes," so the poll will overestimate the public's support. 39') D 40) E 41) The housing classification selected might not be a representative group of the population (undercoverage). In fact the housing classification might be made up of residents with similar viewpoints on property taxes, different from the views of the nonresidents. 4:2) Voluntary Response Bias: individuals with strong opinions or who have reason to need fire equipment would sign. (0] possibly no one volunteers to pay an extra tax.) 43) E 44) C 45) E 46) C 14 ...
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Chapter 12 Review Problems - Chapter 12 Sample Surveys...

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