Exam 5: Sampling: Surveys and How to Ask Questions

Use the following information for questions: According to a Gallup poll, about 90% of all American adults owned a cell phone at the time of the poll. The results are based on telephone interviews with a randomly selected national sample of 998 adults, 18 years and older. The margin of error was reported to be 3.5%. -Which of the following statements correctly interprets the reported margin of error of 3.5%?

Which of the following types of bias could not be caused by improper wording of questions?

For a short mid-term survey of his students, a Graduate Student Instructor has put four questions on a piece of paper. He is planning to hand these out this afternoon. The last two questions are: (1) "What grade do you think you are getting in the course?" and (2) "What grade would you give the instructor so far?" Both questions can be answered with A, B, C, D, or F. What is a potential problem with these questions?

Use the following information for questions: These questions pertain to how to collect a random sample of 800 airline passengers from 100 particular flights leaving San Francisco International Airport. Assume there are 200 passengers aboard each flight. -Describe how to draw the sample as a systematic sample from these flights.

Use the following information for questions: The next question are based on a survey of 500 students living in campus dormitories. Questionnaires were mailed to each of the 500 students. The questionnaire asked if they had ever stolen a bicycle or not. The sample proportion who said they had stolen a bicycle was used to estimate the proportion of all students on campus who had ever stolen a bicycle. -Describe why response bias could be a problem for this survey.

When a representative sample is selected but only a small proportion are actually contacted, the problem is called

Which of the following is the best example of a population from which a cluster sample would be easier to obtain that a simple random sample?

Use the following information for questions: The next question are based on a survey of 500 students living in campus dormitories. Questionnaires were mailed to each of the 500 students. The questionnaire asked if they had ever stolen a bicycle or not. The sample proportion who said they had stolen a bicycle was used to estimate the proportion of all students on campus who had ever stolen a bicycle. -Describe why non-response bias could be a problem for this survey.

A student survey to find out whether more classes should be offered in the evening was mailed to all enrolled students at a university. Explain what a potential difficulty with this method is.

Explain what is wrong with the following statement: "When a survey is mailed out to 500 people and only 150 respond, this results in a bias called response bias."

A television news program asks viewers to log onto their website and vote on a different issue each day. The website allows visitors to select one of two choices and submit a vote. The results of the poll are reported the next day on the news program. The population to which the results of these polls can be extended is

A librarian wants to gather data on the number of times books of fiction are checked out during the year. The library has 2000 books of fiction, of which 500 are murder mysteries, 400 are science fiction, and the rest are "other". She decides to sample 120 books. Suppose the librarian takes the next 120 fiction books that are turned in and calculates the average number of times these books were checked out in the last year. What sampling technique was used?

Use the following information for questions: Olivia wants to learn a foreign language. To get an idea of how satisfied other students were after taking a foreign language course, she decides to take a random sample of 20 students. -If Olivia randomly selects one class among all the foreign language classes taught that year, and then interviews all students in that class, the sampling method is a

Use the following information for questions: Decide if the sample is representative (or not) of the population for the question of interest. -What proportion of people intends to vote in the next presidential election? Sample: 100 baseball fans at a baseball game. Population: All voters in the next presidential election.

Children at a Kindergarten school are divided into three groups: Those who are the oldest/first child (there are 200 of them, call this Group I), those who are the second child (there are 150, call this Group II), and those who are the third (or even fourth or fifth) child (there are 75, call this Group III). The social worker at the school will take a sample to find out how many sleepovers they have had (without parents) at a friend's house. She suspects that first-borns do not get as many as later children, so she decides to take a simple random sample of 15 children from each of the three groups. What sampling technique will be used to obtain the sample of children?

Use the following information for questions: Decide if the sample is representative (or not) of the population for the question of interest. -What is the average number of letters on a page in Webster's unabridged dictionary? Sample: The first page for each of the 26 letters in the alphabet. Population: All pages in the dictionary.

Consider the following survey question: "Shouldn't federal funding not be reduced for HIV awareness programs, since many in U.S. misunderstand the information about an HIV vaccine?" Which of the following types of bias is this question an example of?

There are five cities in a politician's district but redistricting has been proposed for the state. The politician would like to know which city he should try to remove from his district. He plans to conduct a survey to find out his approval rating. Which one of the following sampling plans would be most useful for his purposes?

For which of the following situations would a census be more useful than a sample survey?

A telephone survey was planned to ask people whether they planned to watch the next Super Bowl. Explain why non-response bias may be a problem for this survey.