Question 1

Which of the following best describes the science of statistics?

Accepted Answer

The study of how to collect, organize, summarize, and analyze data to answer questions or draw conclusions.

Question 2

A researcher wants to know the average height of all college students in the United States. She collects data from 500 students at her university. In this scenario, what is the population?

Accepted Answer

All college students in the United States.

Question 3

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

Accepted Answer

Favorite type of music (rock, pop, jazz, classical)

Question 4

Suppose you want to determine if a new medication reduces blood pressure. Which type of study is required to establish causality?

Accepted Answer

An experiment where participants are randomly assigned to treatment and control groups.

Question 5

In a two-way table summarizing survey responses, what does the cell in the table represent?

Accepted Answer

The number of respondents with a specific combination of two categorical variables.

Question 6

A poll reports that 6 in 10 Americans are proud of the US today. This result is most likely based on:

Accepted Answer

A sample of Americans.

Question 7

Which of the following best describes the placebo effect?

Accepted Answer

A participant experiences a change after receiving a harmless treatment, believing it is real.

Question 8

Which of the following is a numerical variable?

Accepted Answer

Number of injuries in a sports season

Question 9

If a study finds an association between drinking coffee and developing cancer, but does not randomly assign participants to groups, what type of study is this?

Accepted Answer

Observational study

Question 10

Which of the following is NOT a 'gold standard' feature of a well-designed experiment?

Accepted Answer

Allowing participants to choose their group

Question 11

A researcher wants to know if a new teaching method improves test scores. She randomly assigns students to either the new method or the traditional method. What is the treatment variable?

Accepted Answer

The teaching method used

Question 12

Given the formula for injury rate: $$	ext{Injury Rate} = \frac{\# 	ext{Injuries}}{\# 	ext{Exposures}}$$, what is the injury rate if there are 20 injuries in 500 exposures?

Accepted Answer

$$0.04$$

Question 13

Which of the following best explains why random assignment is important in experiments?

Accepted Answer

It helps balance out differences between groups to minimize bias.

Question 14

A study reports that 'students who sleep more tend to have higher GPAs.' Which of the following can be concluded from this statement?

Accepted Answer

There is an association between sleep and GPA, but causality is not established.

Question 15

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

Accepted Answer

The average income of 1,000 randomly selected households in a city.

Question 16

In a double-blind experiment, who is unaware of the group assignments?

Accepted Answer

Both the participants and the researchers

Question 17

Which of the following is a reason why anecdotal evidence is not reliable for establishing causality?

Accepted Answer

It is based on a single story and lacks control over variables.

Question 18

A two-way table shows that 30% of male respondents 'strongly agree' with a statement. If there are 400 male respondents, how many 'strongly agree'?

Accepted Answer

$$0.3 	imes 400 = 120$$

Question 19

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

Accepted Answer

A group that does not receive the treatment or characteristic of interest.

Question 20

If a study uses a sample to make inferences about a population, which of the following must be true for the results to be valid?

Accepted Answer

The sample must be representative of the population.

Chapter 1: Introduction to Data and Statistics

Guida di studio - Domande di pratica

Study guide - Flashcard