Question 1

Which of the following best describes the difference between a population and a sample in statistics?

Accepted Answer

A population is the complete collection of all data, while a sample is a subcollection selected from the population.

Question 2

A researcher wants to estimate the average amount of time college students spend studying per week. She surveys 200 randomly selected students from a university with 20,000 students. In this context, what is the population?

Accepted Answer

All 20,000 students at the university.

Question 3

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

Accepted Answer

A radio station asks listeners to call in and vote on a topic.

Question 4

Why are voluntary response samples generally considered unreliable for making conclusions about a population?

Accepted Answer

They are likely to be biased because respondents choose to participate.

Question 5

A study finds that 98 out of 100 randomly selected births are girls. According to statistical significance, is this result likely due to chance?

Accepted Answer

No, because the probability of this happening by chance is very low (less than 5%).

Question 6

Suppose a new medication reduces blood pressure by an average of 1 mmHg, and this result is statistically significant. Which of the following best describes the practical significance of this finding?

Accepted Answer

The result is statistically significant, but may not be practically significant because the reduction is very small.

Question 7

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

Accepted Answer

Reporting sample data instead of measuring it directly.

Question 8

A survey asks: 'Do you agree that the new recycling program is beneficial and should be expanded?' What is the main issue with this question?

Accepted Answer

It is a loaded question that may bias responses.

Question 9

If a study reports that 150% of students passed an exam, what is the main statistical issue?

Accepted Answer

Percentages over 100% are often misleading and not justified.

Question 10

Which of the following best describes the three main steps in conducting a statistical study?

Accepted Answer

Prepare, analyze, and conclude.

Question 11

A researcher wants to determine if there is a relationship between the number of pleasure boats and manatee fatalities in Florida. Which of the following is the most important first step?

Accepted Answer

Consider the context, source, and sampling method of the data.

Question 12

Which of the following formulas correctly represents the calculation of a percentage?

Accepted Answer

$$	ext{Percentage} = \frac{	ext{Part}}{	ext{Whole}} 	imes 100$$

Question 13

A study uses a sample of 30 carbon monoxide detectors out of 38 million installed in the U.S. The sample found 12 failures. What is the main objective of this study?

Accepted Answer

To draw a conclusion about all 38 million detectors based on the sample.

Question 14

Which of the following best illustrates the concept of nonresponse in a survey?

Accepted Answer

Some people refuse to answer or are unavailable.

Question 15

A company claims their product increases the chance of having a girl from 48.8% to 52%. If this result is statistically significant, what should be considered before recommending the product?

Accepted Answer

Whether the increase is practically significant and justifies the cost.

Question 16

Which of the following is NOT a recommended practice when collecting sample data?

Accepted Answer

Allowing respondents to self-select into the sample.

Question 17

Which of the following best describes statistical significance?

Accepted Answer

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

Question 18

Which of the following is an example of a misleading conclusion in statistics?

Accepted Answer

Stating that a treatment is effective based on a biased sample.

Question 19

A survey asks participants to report their own weight. What is a potential issue with this method?

Accepted Answer

Self-reported data may be inaccurate compared to measured data.

Chapter 1: Introduction to Statistics – Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard