quiz 2

A statistics recitation has 30 students. The presenter wants to call an SRS of five students from the recitation to ask where they use a computer for the online exercises. The presenter labels the students 01, 02, ..., 30 and enters the table of random digits at this line: 09731 03453 76165 39241 87853 32459 26056 31424 80371 65103 62253 22490 61181 The SRS contains the students labeled: 09, 73, 10, 34, 53. 09, 10, 34, 16, 24. 09, 10, 16, 24, 26. 09, 10, 16, 24, 24.

09, 10, 16, 24, 26.

Suppose you want to take a simple random sample of size 6 from the 20 participants in your Zumba exercise class. You label the students 01 to 20 in alphabetical order by last name. In the table of random digits, you read the entries 45149 32992 75730 66280 03819 56202 02938 70915 The six participants in your selected sample have labels: 45, 14, 93, 29, 92, 75. 14, 06, 03, 02, 02, 09. 14, 06, 03, 02, 09, 15. 14, 06, 03, 19, 02, 09.

14, 06, 03, 02, 09, 15.

The sports section of the East Mule Shoe Gazette runs a weekly question that readers can answer online. After the local university's football squad was beaten by its rival for the forty-second straight season, the question was "Do you think that the coach needs to go?" Of the 182 people who responded, 89 percent said Yes. The weekly question posted by the East Mule Shoe Gazette is an example of: A voluntary response sample. A simple random sample. A census.

A voluntary response sample.

Which of the following is not true of a simple random sample of size 1000 chosen from a population of size 4 million? Every pair of individuals has the same chance of being included in the sample as every other pair of individuals. Every individual in the population has the same chance of selection as every other individual. Every set of 1000 individuals has the same chance of being in the sample as every other set of 1000 individuals. Every individual of the population has a chance of 1-in-1000 of being included in the sample.

Every individual of the population has a chance of 1-in-1000 of being included in the sample.

The sports section of the East Mule Shoe Gazette runs a weekly question that readers can answer online. After the local university's football squad was beaten by its rival for the forty-second straight season, the question was "Do you think that the coach needs to go?" Of the 182 people who responded, 89 percent said Yes. When people say that the newspaper poll is biased, they mean that: Responding was voluntary, and only those with access and interest would answer. Students may have a different opinion from townspeople. Repeated polls would give results that are very different from each other. The question asked shows a preference on a gender or racial bias.

Responding was voluntary, and only those with access and interest would answer.

This type of sampling uses the idea of "drawing names out of a hat" to produce a sample of individuals. Voluntary response sampling. Simple random sampling. Convenience sampling. Biased.

Simple random sampling.

A teacher writes the names of her 30 students on small pieces of paper and places them into a box. She then draws out five names to select students to participate in a survey. These five students are: a census. the population. a voluntary response sample. a simple random sample of the class.

a simple random sample of the class.

A local talk radio station conducts a poll to determine if its listeners favor or oppose the president's proposed actions on judicial appointments. To express their opinions, listeners are asked to call, email, or text-message the radio station. The poll results in 89.38 percent of the responders opposing the proposed judicial appointments. What type of sampling was used in this situation? This is a census. This is a simple random sample. This is a voluntary response sample. This is a convenience sample.

This is a voluntary response sample

A table of random numbers is used to select 30 students from a statistics class to rate a statistics video. The ratings that these students give are used to estimate the ratings that would be given if the entire class were asked to rate the video. This type of sample is: a biased sample. a sample that avoids bias. a census. voluntary response sample.

a sample that avoids bias.

In a table of random digits: the pair 00 can appear, but 000 is not random and can never appear in the table. a specific pair such as 00 cannot be repeated until all other pairs have appeared. each pair of digits 00, 01, 02, ..., 99 appears exactly once in any row of the table. any pair of entries is equally likely to be any of the one-hundred possible pairs 00, 01, 02, ..., 99.

any pair of entries is equally likely to be any of the one-hundred possible pairs 00, 01, 02, ..., 99.

Bias in a sampling method is: any systematic error that tends to occur in the same direction every time you use this sampling method. the random error due to using chance to select a sample. any error due to practical difficulties such as contacting the subjects selected. any error in the sample result, that is, any deviation of the sample result from the truth about the population.

any systematic error that tends to occur in the same direction every time you use this sampling method.

The president of a university sends surveys to and receives answers from all 21 board members to better understand their positions about upcoming budget issues. The president has conducted a: simple random sample of the board. census. convenience sample. voluntary response sample.

census.

For a sample to be a simple random sample of size n: n must be a large number. the variability must be small. the size of the population must be smaller than n. every collection of n individuals must have the same chance to be in the sample actually chosen.

every collection of n individuals must have the same chance to be in the sample actually chosen.

We select a sample in order to: bias the results toward a certain answer. get information only about the sample. take a census. get information about some population.

get information about some population.

Voluntary response polls almost always suffer from: randomization. no bias. high bias. low bias.

high bias.

For a class project, you want to survey students at your school for their opinions about the importance of studying. You go to the campus library and survey two hundred students as they are leaving the library. In this situation, your survey results will: be exact since the information came from a census. likely be biased since most students leaving the library were there to study. likely be biased since typically only people with strong opinions will participate. be very accurate since the information came from a simple random sample.

likely be biased since most students leaving the library were there to study.

A local talk radio station conducts a poll to determine if its listeners favor or oppose the president's proposed actions on judicial appointments. To express their opinions, listeners are asked to call, email, or text-message the radio station. The poll results in 89.38 percent of the responders opposing the proposed judicial appointments. In this situation, 89.38 percent is: likely to overestimate the true percentage since, typically, only people with strong (and usually negative) opinions will respond. likely to underestimate the true percentage since, typically, only people with strong (and usually positive) opinions will respond. exact since it came from a census. very accurate since it came from a simple random sample.

likely to overestimate the true percentage since, typically, only people with strong (and usually negative) opinions will respond.

A(n) ____ is the subset of units that the experimenter actually measures. survey sample individual population

sample

Every conceivable group of people of the required size has the same chance of being in the selected sample when we use a: convenience sample. census. simple random sample. voluntary response sample.

simple random sample.

An editorial writer for the East Mule Shoe Gazette wants to measure public support for a discontinued construction project that has left a city-block-size hole in the middle of the East Mule Shoe downtown area. So he uses his lunch hour one day to walk down the block adjacent to the project and interview the first 25 people who will talk to him about it. The newspaper asks readers to comment on its survey of local opinion. Readers say that: this is a simple random sample. The results are not biased, but the sample is so small that variation will be high. the sampling method is biased. It will almost certainly underestimate the level of support among all East Mule Shoe residents. the sampling method is biased. It will almost certainly overestimate the level of support among all East Mule Shoe residents. this is a census because all citizens had a chance to be asked. It gives very accurate results.

the sampling method is biased. It will almost certainly overestimate the level of support among all East Mule Shoe residents.