Understanding Populations And Samples Quiz

1) A parameter is to a population as a statistic is to a:

Census

Sample

Model

Survey question

A statistic is from a sample.

Explanation

A statistic is from a sample.

2) A survey asks 200 randomly selected city residents about commute time to estimate the city's average commute time. What is the sample?

All commuters in the city

All workers in the state

The 200 residents surveyed

The city’s transportation department

The sample is the smaller group actually surveyed → the 200 residents.

Explanation

The sample is the smaller group actually surveyed → the 200 residents.

3) Why do researchers use samples instead of surveying entire populations?

Sampling is faster and less costly while still giving reliable estimates

Samples always give exact results

Populations never change

Populations are always too small to measure

Sampling saves time and money.

Explanation

Sampling saves time and money.

4) A school principal wants to know the average number of books students read per year in the entire school. Which is the population?

The principal

A randomly selected 50 students

The students who join the book club

All students in the school

The population is the whole group you care about → here, all students in the school.

Explanation

The population is the whole group you care about → here, all students in the school.

5) Which scenario best describes a population parameter?

The average test score of 30 students in a sample

The average test score predicted from a model

The median test score from a classroom experiment

The true average test score of all students in a district

A parameter is a true value for the entire population.

Explanation

A parameter is a true value for the entire population.

6) Which is the best reason to use a random sample?

It helps reduce bias and makes the sample representative

It is easier to survey friends

It guarantees the smallest sample size

It ensures the highest possible mean

Random sampling helps make the sample representative.

Explanation

Random sampling helps make the sample representative.

7) Which is an example of a biased sample?

Randomly selecting households from the city’s address list

Using a computer to randomly generate phone numbers

Surveying only people at a gym about weekly exercise habits

Selecting every 10th person entering a grocery store

People at a gym are likely to exercise more.

Explanation

People at a gym are likely to exercise more.

8) A university wants the average GPA... sample statistic?

The average GPA of the 600 selected students

The true average GPA

List of majors

Number of students

The sample statistic is the mean of sampled students.

Explanation

The sample statistic is the mean of sampled students.

9) Which plan is most likely to introduce voluntary response bias?

Plan B

Plan C

Plan D

Plan A

Plan C uses volunteers from social media.

Explanation

Plan C uses volunteers from social media.

10) Which statement best summarizes the purpose of sampling?

To avoid studying the population

To guarantee exact values

To infer about a larger population

To make data subjective

We sample to learn about the population.

Explanation

We sample to learn about the population.

11) Which sample is most likely to be representative?

Sample X

Sample Y

Sample Z

Both X and Y

Sample X uses a random household mailing list.

Explanation

Sample X uses a random household mailing list.

12) A team wants to estimate the average height of oak trees in a forest. Which is the best method?

Measure the tallest trees only

Randomly select and measure a set of trees across the forest

Measure only trees near the entrance

Ask hikers to guess the average height

Randomly measuring trees across the forest gives a fair picture.

Explanation

Randomly measuring trees across the forest gives a fair picture.

13) Which plan describes the population?

Plan B

Plan C

Plan D

Plan A

Plan A uses all 9,600 students.

Explanation

Plan A uses all 9,600 students.

14) Which sample is most likely to be biased high for extracurricular hours?

Sample X

Sample Y

Sample Z

None

Sample Y is from a competitive sports event.

Explanation

Sample Y is from a competitive sports event.

15) Which statement is most accurate about Sample Z?

It is a census

It may underrepresent students not in the two selected schools

It is a stratified sample

It uses voluntary response

Sample Z includes only two schools.

Explanation

Sample Z includes only two schools.

16) Which statement is true about populations and samples?

A sample is a subset of a population

A sample is always larger than a population

A population is a subset of a sample

Samples and populations are always the same size

A sample is a smaller part.

Explanation

A sample is a smaller part.

17) Which plan is most likely to produce a representative sample?

Plan C

Plan D

Plan B

Plan A

Plan B randomly surveys students.

Explanation

Plan B randomly surveys students.

18) A school district wants to know the percentage of students who prefer online homework. Which is a parameter?

The percentage from a survey of 200 students

The sample size

The margin of error

The true percentage of all students in the district

A parameter is the true value.

Explanation

A parameter is the true value.

19) A researcher studies the average screen time of teenagers... goal?

To replace the population

To make an inference about the population’s average screen time

To create a new population

To find an exact value with no uncertainty

We use the sample to estimate the population.

Explanation

We use the sample to estimate the population.

20) Which plan is most likely to overrepresent students from a single environment?

Plan A

Plan B

Plan D

None

Plan D surveys only one school.

Explanation

Plan D surveys only one school.

Understanding Populations and Samples Quiz

1) A parameter is to a population as a statistic is to a:

2)

What first name or nickname would you like us to use?

2) A survey asks 200 randomly selected city residents about commute time to estimate the city's average commute time. What is the sample?

3) Why do researchers use samples instead of surveying entire populations?

4) A school principal wants to know the average number of books students read per year in the entire school. Which is the population?

5) Which scenario best describes a population parameter?

6) Which is the best reason to use a random sample?

7) Which is an example of a biased sample?

8) A university wants the average GPA... sample statistic?

9) Which plan is most likely to introduce voluntary response bias?

10) Which statement best summarizes the purpose of sampling?

11) Which sample is most likely to be representative?

12) A team wants to estimate the average height of oak trees in a forest. Which is the best method?

13) Which plan describes the population?

14) Which sample is most likely to be biased high for extracurricular hours?

15) Which statement is most accurate about Sample Z?

16) Which statement is true about populations and samples?

17) Which plan is most likely to produce a representative sample?

18) A school district wants to know the percentage of students who prefer online homework. Which is a parameter?

19) A researcher studies the average screen time of teenagers... goal?

20) Which plan is most likely to overrepresent students from a single environment?