Exam 4: Sample Surveys in the Real World

A simple random sample of people is collected and their blood pressures are measured by one of several lab assistants. One of the lab assistants incorrectly reads the blood pressure gauge and records erroneous data. Which of the following types of errors is present here?

Bias can result from

A probability sample is a

A(n) __________ is a list of units from which a sample is chosen.

Professional sample surveys use careful random samples, usually by randomly dialing telephone numbers, to come close to an SRS. But the results that a sample survey actually obtains may be strongly biased because

Which of the following sources of error is included in the margin of error?

A poll conducted telephone interviews with 1497 adults. These 1497 people make up the

To obtain student opinions on a particular issue, students were identified by major, and five students were randomly selected from within each major to be interviewed. This is an example of

A recently conducted poll omitted people without telephones, and it also left out Alaska and Hawaii residents to reduce cost. These omissions may cause a small bias. If so, that bias is

When a sample survey asks people about their age or some physical characteristic, such as weight, some people who feel self-conscious may not give accurate responses.

Professor Lilli Gans wishes to study the relationship between a person's zodiac sign and his or her political opinions. She obtains the birthdays of all 816 students enrolled in her Astrology 101 course. Then she uses a random digits table to choose 10 students from each of the twelve zodiac signs. For example, students born from March 21 until April 19 have the Aries zodiac sign, and Professor Gans chooses 10 Aries students at random. She uses a different part of the table of random digits to choose students having each sign. After obtaining her sample, Professor Gans has the selected students fill out a questionnaire. One of the questions in Professor Gans's questionnaire asks whether the student has ever given money to the American Nazi Party. Any students who have done so are likely to lie and say "No," rather than admit the truth. This is an example of

A sample that is chosen in stages is a sample in which

A pollster wants to ask a sample of undergraduates at State Tech how they feel about a proposal to build a new dorm in the place of the school's largest commuter parking lot. Opinions may differ depending on whether the student is a commuter or resident, so the pollster takes separate SRSs of commuters and resident students and combines them to form his sample. He used a:

The announced margin of error for a sample survey covers

When we take a census, we

In 2014 Scotland was considering independence from England, going so far as to take a referendum vote. One opinion poll taken at the time showed that 51 percent of Scots favored "independence." In another poll taken at that same time, only 34 percent favored being "separate" from England. The primary reason these results differed by so much is that:

Which of the following is NOT a potential problem with Internet surveys?

One source of error in pre-election polls is that some people in the sample say they are undecided, but in fact, they know whom they are going to vote for. This is an example of:

You want to know the opinions of American school teachers about establishing a national test for high school graduation. You obtain a list of the members of the National Education Association (the largest teachers' union) and mail a questionnaire to 2500 teachers chosen at random from this list. In all, 1347 teachers return the questionnaire. The sampling frame is

A report from the U.S. Department of Health and Human Services estimated that 10.2 percent of Americans in 2014 had used illicit drugs with a margin of error of ± 0.18 percent. Suppose that many of those asked about their behavior give an answer that isn't the truth because they fear that their answer will go to law enforcement officials.