### All AP Statistics Resources

## Example Questions

### Example Question #1 : How To Define A Survey Population

A company asks you to conduct a survey to discover what consumers generally want. What should the survey population be?

**Possible Answers:**

Past consumers

All possible consumers

Future consumers

All of the company's customers

**Correct answer:**

All possible consumers

The company wants a survey on what consumers want. That means they are interested in all possible consumers. The other groups are too specific.

### Example Question #1 : How To Conduct A Sample Survey

Your AP Statistics teacher asks you to conduct a survey to determine the most popular cereal brand at your high school. Which of the following should be the survey population in your study?

**Possible Answers:**

All high school students in the United States

Students in your grade level

Students in your AP Statistics Class

All high school students in your city

All students in your high school

**Correct answer:**

All students in your high school

Since your teacher has asked that you determine the most popular cereal brand at **your high school**, the survey population should be limited to only your high school. Other students' preferences of cereal brands around the nation will have no impact on the survey results.

Additionally, surveying only students in your AP Statistics class or only students in a particular grade level would not be representative of all students in your high school. Therefore, the correct survey population is all students in your high school.

### Example Question #1 : How To Conduct A Sample Survey

Shawn would like to determine what the most popular television channel is in his town, called Hearne.

Which of the following would be an appropriate target population for the survey?

**Possible Answers:**

Residents of the town whose contact information can be found in the local directory

Attendees of a mass at a local Church

Students at the local high school

Purchasers of a television at the local electronics store

Shoppers at the local grocery store

**Correct answer:**

Residents of the town whose contact information can be found in the local directory

Since Shawn would like to know the most popular television channel in his town, he must include all residents of the town in his target population. The sample must come from the directory and each person in the directory should have an equal chance of being selected. The incorrect options are too narrowly focused and are not representative of the town.

### Example Question #1 : How To Define A Sample Set

Which of the following is a continuous variable?

i. The average weight of a newborn puppy

ii. The number of snow days during the last month

iii. The amount of time that it takes to read a book

**Possible Answers:**

None of the above

i only

i and iii

i and ii

ii and iii

**Correct answer:**

i and iii

A continuous variable can take on an infinite continuum of possible real number values. Weight and the amount of time to read a book are continuous because it is impossible to write down all the distinct potential values.

### Example Question #1 : How To Define A Sample Set

For which of these is a binomial probability model most reasonable?

**Possible Answers:**

The colors of the gummy bears in a particular bag of gummy bears from a randomly selected store rack.

The number of cards drawn from a deck until the two jokers are drawn.

The number of times a randomly selected college student has gone to the beach in the last year.

The number of people surveyed until someone who has no pets is found.

The number of times, out of attempts, that a player can throw a basketball through the hoop from feet away.

**Correct answer:**

The number of times, out of attempts, that a player can throw a basketball through the hoop from feet away.

A binomial model counts the number of successes out of a specific number of attempts at a task when each attempt has a constant probability of success. The correct choice is the one that specifies the number of attempts.

### Example Question #1 : How To Conduct A Sample Survey

Which of the following is the best way to ensure a sample is representative and unbiased?

**Possible Answers:**

Take a voluntary response sample

Take a random sample

Take a census

Take a convenience sample

None of the other answers

**Correct answer:**

Take a random sample

Taking a random sample is the only data-collecting method that ensures that every set of individuals has an equal chance of being selected for the sample and does not introduce any significant bias. Taking either a voluntary response sample or a convenience sample does not ensure these important aspects, as there is some unwanted selectivity involved in the data being collected. Taking a census is inferior to taking a sample of any sort, as it is both costly and time-consuming.

### Example Question #1 : How To Do A Random Selection For A Survey

John would like to find out what percentage of residents in his neighborhood enjoy shopping. Which of the following is the best method to randomly select participants to take John's survey?

**Possible Answers:**

John can go to his local grocery store and survey individuals at random to determine if they enjoy shopping

John can sit at the park in his neighborhood and survey every individual that passes by to determine if they enjoy shopping

John can number residents his neighborhood and randomly select residents to survey using a random number generator

There is no effective way to randomly select participants to be surveyed

John can go to his local mall and survey individuals at random to determine if they enjoy shopping

**Correct answer:**

John can number residents his neighborhood and randomly select residents to survey using a random number generator

The best answer is the choice that reduces the amount of bias in the selection of survey participants. Surveying local residents at a grocery store, neighborhood park, or shopping mall would introduce selection bias into the survey since every member of the target population does not have an equal chance of being selected. Using the random number generator, every single person in the neighborhood has an equal chance of being selected to take the survey.

### Example Question #1 : How To Conduct A Sample Survey

To find the percentage of households in a town who own more than one motor vehicle, a survey will ask the next 100 drivers at a popular gas station if there is more than one motor vehicle in their household. Is this survey biased and if so, what is the main type of bias?

**Possible Answers:**

None of the other answers are correct

No, the survey is representative of the local population

Yes, voluntary response bias

Yes, non-response bias

Yes, undercoverage bias

**Correct answer:**

Yes, undercoverage bias

Because the survey is being conducted on drivers at a gas station, people/households who do not own a motor vehicle will not be included in the survey.

### Example Question #1 : How To Conduct A Sample Survey

Identify the type of bias:

A researcher wants to know what proportion of coffee drinkers would pay more than $5 for a coffee drink. The researcher asks the following question:

"Do you agree that $5 is way too much to pay for a simple coffee"

**Possible Answers:**

Undercoverage

Leading question

Voluntary response bias

Social desirability

Nonresponse bias

**Correct answer:**

Leading question

By using the words *way too much* and *simple coffee*, the researcher is introducing bias into their question by causing people to favor one response over another.

To avoid this sampling bias, the researcher should use more neutral wording, such as "Agree or diasgree- I would pay $5 or more for a coffee drink."

### Example Question #1 : How To Identify Sources Of Bias In A Survey

Identify the type of bias:

A researcher wants to know whether students at a particular university have ever cheated on a test. The researcher walks up to 100 random students and asks them the following question:

"Have you ever cheated on a test or exam?"

**Possible Answers:**

Social desirability

Leading questions

Voluntary response bias

Nonresponse bias

Undercoverage

**Correct answer:**

Social desirability

Many people are reluctant to be honest about their bad behaviors, especially if they don't believe the survey is confidential. This will cause participants to be more likely to respond with whatever is more socially acceptable.

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