Question 1

Which of the following best describes the main purpose of statistics as a science?

Accepted Answer

To plan studies and experiments, obtain data, and then organize, summarize, present, analyze, and interpret those data to draw conclusions.

Question 2

A researcher wants to estimate the average height of all university students. She randomly selects 200 students from the university and records their heights. In this scenario, what is the population?

Accepted Answer

All university students.

Question 3

Which of the following is a key difference between a census and a sample?

Accepted Answer

A census collects data from every member of a population, while a sample collects data from a subcollection of the population.

Question 4

Which of the following is an example of a voluntary response sample?

Accepted Answer

A television show asks viewers to call in and vote on an issue.

Question 5

Why are voluntary response samples generally considered to be flawed?

Accepted Answer

They are likely to be biased because respondents self-select to participate.

Question 6

A study finds that a new medication reduces blood pressure by an average of 1 mmHg, with a p-value of 0.01. Which of the following statements is correct?

Accepted Answer

The result is statistically significant but may not be practically significant.

Question 7

Which of the following best defines statistical significance?

Accepted Answer

A result is statistically significant if the likelihood of it occurring by chance is less than or equal to 5%.

Question 8

A weight loss program reports an average loss of 2.1 kg after one year, with results that are statistically significant. However, many participants feel this is not worth the effort. What concept does this illustrate?

Accepted Answer

Statistical significance without practical significance

Question 9

Which of the following is a potential pitfall when analyzing survey data?

Accepted Answer

Using loaded or poorly worded questions

Question 10

A survey asks, 'How great do you think our university is?' What is the main issue with this question?

Accepted Answer

It is a loaded question that may bias responses.

Question 11

Which of the following best describes the process of conducting a statistical study?

Accepted Answer

Prepare, analyze, and conclude.

Question 12

Suppose a poll of 186,000 volunteer respondents finds that 67% support a policy, while a random sample of 500 finds only 38% support. Which result is more reliable and why?

Accepted Answer

The 500 random sample, because random sampling reduces bias.

Question 13

Which of the following is NOT a step in the 'prepare' phase of a statistical study?

Accepted Answer

Analyzing the data for outliers

Question 14

A researcher collects data on shoe print lengths and heights of randomly selected males to estimate the height of a criminal at a crime scene. What is the main statistical goal in this context?

Accepted Answer

To determine if there is a relationship between shoe print length and height.

Question 15

Which of the following is a sign that survey results may be unreliable due to nonresponse?

Accepted Answer

A low response rate, increasing the likelihood of bias

Question 16

If a study reports that 120% of people prefer a new product, what is the most likely issue?

Accepted Answer

The percentage is misleading because it exceeds 100%.

Question 17

Which of the following best describes 'data' in the context of statistics?

Accepted Answer

Collections of observations, such as measurements, genders, or survey responses.

Question 18

A study finds that 98 out of 100 random births are girls. Why is this result considered statistically significant?

Accepted Answer

Because the probability of such an extreme outcome by chance is very low (less than 5%).

Question 19

Which of the following is an example of a biased sampling method?

Accepted Answer

Allowing respondents to decide whether to participate in a survey.

Question 20

Which of the following is a recommended first step when analyzing a new data set?

Accepted Answer

Begin with appropriate graphs and exploration of the data.

Introduction to Statistics: Concepts, Data, and Critical Thinking

Guida di studio - Domande di pratica

Study guide - Flashcard