Question 1

Which of the following best describes the science of statistics?

Accepted Answer

The science of collecting, organizing, analyzing, and interpreting data to make decisions.

Question 2

A researcher wants to know the average number of hours all university students in the country spend studying per week. She surveys 500 students from three universities and finds an average of 15 hours. In this context, what is the sample?

Accepted Answer

The 500 students surveyed from three universities.

Question 3

Which of the following statements is an example of a population parameter?

Accepted Answer

The average height of all high school students in a city.

Question 4

A study reports that 21% of 8–11 year-olds have a social media profile, based on a survey of 1,200 children. What is the statistic in this scenario?

Accepted Answer

21%

Question 5

Which of the following best distinguishes between descriptive and inferential statistics?

Accepted Answer

Descriptive statistics summarize and display data; inferential statistics use sample data to draw conclusions about a population.

Question 6

In a study, researchers found that 34% of several hundred retail stores were not storing fish at the proper temperature. What type of value is 34% in this context?

Accepted Answer

A sample statistic

Question 7

Suppose a survey of 9,400 individuals aged 15 and over in the United States found that they spent an average of 5.19 hours per day on leisure and sports activities. Which of the following is true?

Accepted Answer

5.19 hours is a sample statistic because it is based on a subset of the population.

Question 8

A university reports that the average SAT math score of its entire freshman class is 514. What is this value an example of?

Accepted Answer

A population parameter

Question 9

Which of the following scenarios best illustrates the use of inferential statistics?

Accepted Answer

Using data from a sample of patients to estimate the average recovery time for all patients with a certain disease.

Question 10

A study of 1,000 U.S. 401(k) retirement plan participants found that 32% do not know how many years their retirement savings might last. What is the population in this study?

Accepted Answer

All U.S. 401(k) retirement plan participants

Question 11

Which of the following is NOT a correct statement about the difference between a population and a sample?

Accepted Answer

A sample includes all outcomes, responses, or measurements of interest.

Question 12

A medical researcher collects data on the blood pressure of 200 patients in a hospital to estimate the average blood pressure of all patients in the city. Which branch of statistics is primarily being used when making this estimate?

Accepted Answer

Inferential statistics

Question 13

Which of the following best describes a parameter?

Accepted Answer

A numerical description of a population characteristic.

Question 14

A company wants to know the average commute time of its employees. It surveys all 1,200 employees and finds an average of 35 minutes. What is this average an example of?

Accepted Answer

A population parameter

Question 15

Which of the following is an example of using descriptive statistics?

Accepted Answer

Reporting that 18% of adults from households earning less than $30,000 annually do not use the Internet.

Question 16

A study finds that 7 in 10 Americans believe the arts unify their communities. What is the data in this context?

Accepted Answer

The responses from Americans about their beliefs regarding the arts.

Question 17

Which of the following is a correct application of inferential statistics in a real-world scenario?

Accepted Answer

Using a sample of voters to predict the outcome of a national election.

Question 18

Suppose you want to estimate the average number of hours spent on social media by all teenagers in your country. You collect data from 2,000 randomly selected teenagers. Which of the following best describes your approach?

Accepted Answer

You are using a sample to make an inference about a population.

Question 19

A study of 834 employees found that 517 said their jobs were highly stressful. What is the sample proportion of employees who found their jobs highly stressful? (Express your answer as a decimal rounded to two decimal places.)

Accepted Answer

$$ \frac{517}{834} \approx 0.62 $$

Question 20

Which of the following best explains why a sample statistic may differ from a population parameter?

Accepted Answer

A sample is only a subset of the population and may not perfectly represent the entire population.

Introduction to Statistics: Key Concepts and Foundations

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