Question 1

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

Accepted Answer

A population is the entire group of interest, while a sample is a subset of that group.

Question 2

In a survey, 834 employees in the United States were asked if they thought their jobs were highly stressful. Of the 834 respondents, 517 said yes. What is the sample in this scenario?

Accepted Answer

The 834 employees who responded to the survey.

Question 3

Which of the following is an example of a parameter?

Accepted Answer

The average age of all people in the United States.

Question 4

A statistic is best defined as:

Accepted Answer

A numerical description of a sample characteristic.

Question 5

Which branch of statistics involves using sample data to draw conclusions about a population?

Accepted Answer

Inferential statistics

Question 6

A study finds that 21% of 8–11 year-olds have a social media profile. This value is most likely:

Accepted Answer

A statistic, because it is based on a sample of children.

Question 7

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

Accepted Answer

Summarizing the average SAT score of a freshman class using a table.

Question 8

Suppose a researcher wants to estimate the average number of hours college students sleep per night. She surveys 500 students and finds an average of 6.8 hours. Which formula represents the sample mean?

Accepted Answer

$$\bar{x} = \frac{\sum_{i=1}^{n} x_i}{n}$$

Question 9

In a random check of several hundred retail stores, the Food and Drug Administration found that 34% of the stores were not storing fish at the proper temperature. Is this value a parameter or a statistic?

Accepted Answer

Statistic, because it is based on a sample of stores.

Question 10

Which of the following is NOT a function of statistics?

Accepted Answer

Ignoring data that does not fit the hypothesis

Question 11

A study of 1502 U.S. adults found that 18% of adults from households earning less than $30,000 annually do not use the Internet. Which part of the study represents the descriptive branch of statistics?

Accepted Answer

The calculation that 18% of surveyed adults do not use the Internet.

Question 12

Which of the following best describes a data set in statistics?

Accepted Answer

A collection of observations, counts, measurements, or responses.

Question 13

If $$\mu$$ represents the population mean and $$\bar{x}$$ represents the sample mean, which statement is true?

Accepted Answer

$$\bar{x}$$ estimates $$\mu$$ using sample data.

Question 14

A researcher collects data on the number of hours spent studying by 100 randomly selected college students. What type of statistics would be used to summarize the average hours spent?

Accepted Answer

Descriptive statistics

Question 15

Which of the following is an example of inferential statistics?

Accepted Answer

Using sample data to predict the average test score of all students in a university.

Question 16

A survey of 9400 individuals found that such individuals spent an average of 5.19 hours per day engaged in leisure and sports activities. Is this value a parameter or a statistic?

Accepted Answer

Statistic, because it is based on a sample of individuals.

Question 17

Which formula correctly represents the population mean?

Accepted Answer

$$\mu = \frac{\sum_{i=1}^{N} x_i}{N}$$

Question 18

Which of the following statements is true regarding descriptive and inferential statistics?

Accepted Answer

Inferential statistics use sample data to draw conclusions about a population.

Question 19

A study of 1000 U.S. 401(k) retirement plan participants found that the percentage who do not know how many years their retirement savings might last is 32%. What is the population in this study?

Accepted Answer

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

Introduction to Statistics: Key Concepts, Definitions, and Applications

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