Question 1

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

Accepted Answer

The group of interest about which researchers want to make conclusions.

Question 2

A researcher records the blood pressure of 50 patients in a clinic. What is the sample size, and how should it be denoted?

Accepted Answer

The sample size is 50, denoted as $$n = 50.$$

Question 3

Which of the following variables is quantitative?

Accepted Answer

Number of siblings

Question 4

In a study, the variable 'Married' is coded as 0 for 'not married' and 1 for 'married'. How should this variable be classified?

Accepted Answer

Categorical, because the numbers represent categories.

Question 5

Which of the following best describes a census?

Accepted Answer

Data collected from every member of the population.

Question 6

A researcher wants to study the effect of a new drug on blood pressure. She randomly assigns patients to receive either the drug or a placebo. What type of study is this?

Accepted Answer

Randomized experiment

Question 7

Which of the following is an example of response bias?

Accepted Answer

Patients overstating how often they exercise due to social desirability.

Question 8

If a variable is measured in 'hours of work per week', what is its classification and unit?

Accepted Answer

Quantitative; unit is 'hours'

Question 9

Which of the following statements about random samples is TRUE?

Accepted Answer

Random samples are free from sampling bias.

Question 10

A study finds that people who eat more vegetables tend to have lower cholesterol. Which of the following is NOT a possible explanation for this association?

Accepted Answer

The association is always due to cause-and-effect.

Question 11

In a matched-pairs experiment, which of the following is TRUE?

Accepted Answer

Each case receives both treatments in random order, or cases are paired and each gets a different treatment.

Question 12

Which of the following best describes the role of a control group in an experiment?

Accepted Answer

To receive a treatment that will not directly influence the response variable.

Question 13

A variable 'Developed' is based on energy usage per capita and has values 1 (underdeveloped), 2 (developing), and 3 (developed). How should 'Developed' be classified?

Accepted Answer

Categorical, because it groups countries into categories.

Question 14

Which of the following is a key requirement for making valid generalizations from a sample to a population?

Accepted Answer

The sample must be random.

Question 15

A researcher collects data from students who volunteer to participate in a survey about study habits. What type of sampling bias is most likely present?

Accepted Answer

Self-selection (voluntary response)

Question 16

Which of the following is TRUE about the relationship between sample size and accuracy?

Accepted Answer

A small random sample is better than a large non-random sample.

Question 17

In a randomized comparative experiment, what is the main purpose of random assignment?

Accepted Answer

To allow observed associations to be attributed to cause-and-effect.

Question 18

Which of the following best describes a variable in statistics?

Accepted Answer

A characteristic recorded for each case.

Question 19

A study records the responses to the question 'Do you smoke?' with possible answers 'Yes' and 'No'. What are the values of the variable 'Smoke'?

Accepted Answer

The values are 'Yes' and 'No'.

Question 20

Which of the following is TRUE about the placebo effect in experiments?

Accepted Answer

It occurs when participants experience changes simply because they believe they are receiving a treatment.

Introductory Statistics: Data Collection and Study Design

Guida di studio - Domande di pratica

Study guide - Flashcard