Question 1

Which of the following best describes the difference between a population parameter and a sample statistic?

Accepted Answer

A population parameter describes a characteristic of the entire population, while a sample statistic describes a characteristic of a sample.

Question 2

A researcher wants to estimate the average number of hours college students spend studying per week. She surveys 200 randomly selected students from her university. What is the population in this study?

Accepted Answer

All students at her university

Question 3

Which of the following is an example of a systematic sample?

Accepted Answer

Selecting every 10th person who enters a store

Question 4

A news organization wants to estimate the percentage of adults who support a new policy. They randomly select 1,000 adults and find that 54% support the policy. Which of the following best describes the 54%?

Accepted Answer

Sample statistic

Question 5

Which sampling method is most appropriate for ensuring that all subgroups of a population are represented proportionally?

Accepted Answer

Stratified sampling

Question 6

A pharmaceutical company tests a new drug by giving it to one group and a placebo to another group, without telling the participants which group they are in. What type of study is this?

Accepted Answer

Double-blind experiment

Question 7

Which of the following best defines the margin of error in a confidence interval?

Accepted Answer

A value that describes the range of values within which the population parameter is likely to fall

Question 8

Suppose a survey reports that 60% ± 3% of adults support a new law, with 95% confidence. What does the ± 3% represent?

Accepted Answer

The margin of error

Question 9

Which of the following is an example of bias in sampling?

Accepted Answer

Surveying only people who are easily accessible

Question 10

A researcher divides a city into neighborhoods and randomly selects several neighborhoods. She then surveys all residents in those neighborhoods. What sampling method is this?

Accepted Answer

Cluster sampling

Question 11

Which of the following best describes an observational study?

Accepted Answer

Researchers observe subjects without manipulating variables

Question 12

In a clinical trial, neither the participants nor the researchers know who is receiving the treatment or the placebo. This is an example of:

Accepted Answer

Double-blind study

Question 13

A study finds that students who listen to classical music before an exam score higher than those who do not. What is the treatment group in this experiment?

Accepted Answer

Students who listened to classical music

Question 14

Which of the following is a confounding variable in an experiment?

Accepted Answer

A variable that affects the outcome but is not controlled by the researcher

Question 15

A meta-analysis is best described as:

Accepted Answer

A study that combines results from multiple studies to draw a conclusion

Question 16

Which of the following formulas correctly represents a confidence interval for a population proportion $$p$$ based on a sample proportion $$\hat{p}$$ and margin of error $$E$$?

Accepted Answer

$$\hat{p} \pm E$$

Question 17

A researcher wants to study the effect of a new teaching method on student performance. She randomly assigns students to two groups: one uses the new method, the other uses the traditional method. What type of study is this?

Accepted Answer

Experiment

Question 18

Which of the following best describes a variable of interest in a statistical study?

Accepted Answer

A variable that is measured or observed in the study

Question 19

A study collects data on the number of hours people exercise per week and their cholesterol levels. Which variable is the explanatory variable?

Accepted Answer

Number of hours of exercise

Question 20

Which of the following is NOT a reason for using a sample instead of a population?

Accepted Answer

A sample always gives the exact value of the population parameter

Introduction to Statistics: Foundations, Sampling, and Types of Studies

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