Question 1

Which of the following best describes a variable in the context of statistics?

Accepted Answer

A characteristic of an individual that can take different values.

Question 2

Suppose you want to estimate the average height of students in a university. Which sampling method is most likely to produce a representative sample?

Accepted Answer

Randomly selecting students from the entire student list using a random number generator.

Question 3

What is the main purpose of using a simple random sample?

Accepted Answer

To ensure every individual in the population has an equal chance of being selected.

Question 4

A survey asks people to report how many alcoholic drinks they consume per week. Which type of bias is most likely to affect the results?

Accepted Answer

Response bias

Question 5

Which of the following is an example of a quantitative variable?

Accepted Answer

The number of siblings a person has

Question 6

Why is it important for a sample to be representative of the population?

Accepted Answer

So that the results can be generalized to the population.

Question 7

A researcher surveys only people who respond to an online advertisement. What type of bias is most likely present?

Accepted Answer

Selection bias

Question 8

Which of the following best describes an observational study?

Accepted Answer

A study where the researcher does not interfere with the subjects, only collects data.

Question 9

Suppose a survey about illegal drug use is conducted by asking people to fill out a form in front of a police officer. What is the most likely problem with the data collected?

Accepted Answer

Response bias

Question 10

Which of the following is a qualitative variable?

Accepted Answer

The type of transportation used to commute

Question 11

A cluster sample is best described as:

Accepted Answer

Randomly selecting groups (clusters) and including all individuals within those groups.

Question 12

Which of the following statements about non-response bias is correct?

Accepted Answer

It occurs when individuals selected for the sample do not respond and their non-response is related to the variable of interest.

Question 13

A study finds that people who eat more vegetables tend to have lower rates of heart disease. Can we conclude that eating vegetables causes lower heart disease rates? Why or why not?

Accepted Answer

No, because the study is observational and does not establish causation.

Question 14

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

Accepted Answer

Selecting every 10th person from a list after randomly choosing a starting point.

Question 15

Suppose a researcher wants to study the effect of a new drug. Which study design would best allow them to establish causation?

Accepted Answer

A randomized controlled experiment

Question 16

If a sample mean is $$\overline{x} = 62.7$$ inches and the population mean is $$\mu = 63.7$$ inches, what statistical process allows us to infer about the population mean from the sample mean?

Accepted Answer

Inference

Question 17

Which of the following best describes selection bias?

Accepted Answer

A bias that occurs when the sample is not representative of the population due to the way individuals are selected.

Question 18

A researcher assigns numbers to all individuals in a population and uses a random number generator to select a sample. What type of sample is this?

Accepted Answer

Simple random sample

Question 19

Which of the following is NOT a characteristic of a good sample?

Accepted Answer

It includes only individuals who are easy to reach.

Question 20

In a study, the population consists of all adults living in Canada. The sample consists of adults who responded to a mail survey. What is a potential problem with this sample?

Accepted Answer

It may not be representative due to non-response bias.

Chapter 1: Introduction to Statistics, Data, and Sampling

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