Question 1

Which of the following best describes a parameter in statistics?

Accepted Answer

A numerical measurement describing a characteristic of a population.

Question 2

Suppose a researcher surveys 300 students at a university to estimate the average number of hours students study per week. What is the sample in this context?

Accepted Answer

The 300 students surveyed.

Question 3

Which of the following is an example of a quantitative (numerical) variable?

Accepted Answer

The number of books read in a month.

Question 4

A study collects the following data: student ID numbers, test scores, and favorite ice cream flavors. Which variable is an identifier variable?

Accepted Answer

Student ID numbers

Question 5

Which of the following best describes a census?

Accepted Answer

A collection of data from every member of the population.

Question 6

A researcher wants to study the opinions of all residents in a city about a new park. She posts an online survey on the city’s website. Which type of bias is most likely to affect her results?

Accepted Answer

Voluntary response bias

Question 7

Which of the following is an example of discrete data?

Accepted Answer

The number of cars in a parking lot.

Question 8

A sample statistic is used to estimate a population parameter. Which of the following statements is true?

Accepted Answer

Population parameters are typically unknown, so we use sample statistics to estimate them.

Question 9

Which of the following is an example of nominal data?

Accepted Answer

The type of pet owned (dog, cat, bird).

Question 10

A researcher uses a random number generator to select 50 students from a list of all students at a university. What type of sampling method is this?

Accepted Answer

Simple random sampling

Question 11

Which of the following best describes statistical significance?

Accepted Answer

A result that is unlikely to occur by chance even after accounting for sample variation.

Question 12

A researcher wants to study the average commute time of employees in a large company. She divides the employees into departments and randomly selects some departments, then surveys all employees in those departments. What sampling method is she using?

Accepted Answer

Cluster sampling

Question 13

Which of the following is an example of response bias?

Accepted Answer

Survey questions are worded in a way that influences answers.

Question 14

Suppose you want to estimate the proportion of students who smoke at a university. You randomly select every 10th student from an alphabetical list. What sampling method is this?

Accepted Answer

Systematic sampling

Question 15

Which of the following best describes undercoverage bias?

Accepted Answer

A sample is chosen in such a way that some groups in the population are left out.

Question 16

A researcher wants to study the effect of a new teaching method. She randomly assigns students to two groups: one uses the new method, the other uses the traditional method. What is the main advantage of randomization in this context?

Accepted Answer

It helps balance out unknown factors between the groups.

Question 17

Which of the following is a real-world example of continuous data?

Accepted Answer

The amount of rainfall in millimeters during a month.

Question 18

A survey asks, 'How many hours did you sleep last night?' instead of 'How much do you usually sleep?' What is the main benefit of this approach?

Accepted Answer

It reduces response bias by asking about a specific time period.

Question 19

A researcher wants to estimate the average income of households in a city. She samples only households listed in the city’s phone book. What type of bias is most likely present?

Accepted Answer

Undercoverage bias

Question 20

Suppose you want to estimate the average height of all high school students in a large city. You randomly select 5 schools and measure the height of every student in those schools. Which sampling method are you using?

Accepted Answer

Cluster sampling

Introduction to Statistics: Key Concepts and Sampling Methods

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