Question 1

Use the following 
The USStates dataset, used throughout the textbook, contains information on the 50 U.S. states from 2008. A small segment from the dataset is displayed in the following table.
 
-What variable was used to determine that 43.4% of Connecticut state residents have a college degree? Is it categorical or quantitative?

Accepted Answer

The answer of Use the following 
The USStates dataset, used...

Question 2

The ____________________ variable is used to understand or predict values of the ________________________ variable.

Accepted Answer

The answer of The ____________________ variable is used to understand...

Question 3

Use the following 
A group of researchers investigated the effect of media usage (whether or not subjects watch television or use the Internet) in the bedroom on "Tiredness"
during the day (measured on a 50 point scale).
-Identify the variables described and whether they are categorical or quantitative.

Accepted Answer

The answer of Use the following 
A group of researchers...

Question 4

Use the following 
A group of researchers investigated the effect of media usage (whether or not subjects watch television or use the Internet) in the bedroom on "Tiredness"
during the day (measured on a 50 point scale).
-Identify the variables as either explanatory or response variables.

Accepted Answer

The answer of Use the following 
A group of researchers...

Question 5

Use the following 
A group of researchers investigated the effect of media usage (whether or not subjects watch television or use the Internet) in the bedroom on "Tiredness"
during the day (measured on a 50 point scale).
-To collect these data, the researchers randomly selected homes to visit and interviewed the adult member of the household whose birthday was nearest. Is this an experiment or an observational study? Briefly explain.

Accepted Answer

The answer of Use the following 
A group of researchers...

Question 6

Use the following 
A group of researchers investigated the effect of media usage (whether or not subjects watch television or use the Internet) in the bedroom on "Tiredness"
during the day (measured on a 50 point scale).
-Suppose that the researchers found that the individuals who use media in the bedroom tended to be more tired during the day than those who do not. Would it be appropriate for the researchers to conclude that using media in the bedroom causes tiredness during the day? Briefly explain why or why not.

Accepted Answer

The answer of Use the following 
A group of researchers...

Question 7

A population includes all individuals or objects of interest.

Accepted Answer

A population is defined as the entire group of individuals or objects that are the focus of a statistical study.

Question 8

A population is a subset of the sample.

Accepted Answer

A sample is a subset of a population, not the other way around. A population includes all members of a defined group, while a sample consists of some members selected from that group.

Question 9

A biased sample is one that does not accurately reflect or represent the population.

Accepted Answer

A biased sample is one that systematically overrepresents or underrepresents certain segments of the population, leading to inaccurate conclusions about the entire population.

Question 10

Use the following 
State whether the data are best described as a population or a sample.
-The makers of M&M's state that when they package their candies they thoroughly mix the colored candies together and randomly put them into packages. A student purchases a bag of Milk Chocolate M&M's from the vending machine.

Accepted Answer

The answer of Use the following 
State whether the data...

Question 11

Use the following 
State whether the data are best described as a population or a sample.
-A professor wants to schedule a review session for an exam. He asks all students enrolled in the course their preferred time, and they all respond.

Accepted Answer

The answer of Use the following 
State whether the data...

Question 12

Use the following 
State whether the data are best described as a population or a sample.
-A researcher has identified a beach with a substantial number of driftwood logs. She randomly chooses 30 logs and takes core samples from those logs.

Accepted Answer

The answer of Use the following 
State whether the data...

Question 13

Use the following 
State whether the data are best described as a population or a sample.
-A football fan recorded the number of rushing yards for all NFL running backs who played last season.

Accepted Answer

The answer of Use the following 
State whether the data...

Question 14

Association implies causation.

Accepted Answer

Association implies a relationship between two variables, but it does not prove that one variable causes the other. Causation requires further evidence to establish a cause-and-effect relationship.

Question 15

In elementary school (Grades 1 through 6) there is a strong association between a child's height and reading ability. What is a possible confounding variable that would help explain this relationship? Explain briefly.

Accepted Answer

The answer of In elementary school (Grades 1 through 6)...

Question 16

A sample of college age students shows an interesting association between hair length (in inches) and height (also in inches). On average, shorter students tend to have longer hair. What is a possible confounding variable that would help explain this relationship? Explain briefly.

Accepted Answer

The answer of A sample of college age students shows...

Question 17

Use the following 
A 2012 study investigated the impact of psychological stress on men's judgements of female body size. The men were randomly assigned to one of two groups; one group was assigned to participate in a stressful task while the other group did not take part in the task. Then the men were asked to rate the attractiveness of female bodies varying in size from emaciated to obese.
-What are the cases in this study?

Accepted Answer

The answer of Use the following 
A 2012 study investigated...

Question 18

Use the following 
A 2012 study investigated the impact of psychological stress on men's judgements of female body size. The men were randomly assigned to one of two groups; one group was assigned to participate in a stressful task while the other group did not take part in the task. Then the men were asked to rate the attractiveness of female bodies varying in size from emaciated to obese.
-Briefly explain why this is an experiment and not an observational study.

Accepted Answer

The answer of Use the following 
A 2012 study investigated...

Question 19

Use the following 
A 2012 study investigated the impact of psychological stress on men's judgements of female body size. The men were randomly assigned to one of two groups; one group was assigned to participate in a stressful task while the other group did not take part in the task. Then the men were asked to rate the attractiveness of female bodies varying in size from emaciated to obese.
-Identify the explanatory variable in this experiment.

Accepted Answer

The answer of Use the following 
A 2012 study investigated...

Question 20

Use the following 
A 2012 study investigated the impact of psychological stress on men's judgements of female body size. The men were randomly assigned to one of two groups; one group was assigned to participate in a stressful task while the other group did not take part in the task. Then the men were asked to rate the attractiveness of female bodies varying in size from emaciated to obese.
-Identify the response variable in this experiment.

Accepted Answer

The answer of Use the following 
A 2012 study investigated...

Quiz 1: Collecting Data

The variable is used to understand or predict values of the ____ variable.

Use the following A group of researchers investigated the effect of media usage (whether or not subjects watch television or use the Internet) in the bedroom on "Tiredness" during the day (measured on a 50 point scale). -Identify the variables as either explanatory or response variables.

A population includes all individuals or objects of interest.

A population is a subset of the sample.

A biased sample is one that does not accurately reflect or represent the population.

Use the following State whether the data are best described as a population or a sample. -A professor wants to schedule a review session for an exam. He asks all students enrolled in the course their preferred time, and they all respond.

Use the following State whether the data are best described as a population or a sample. -A researcher has identified a beach with a substantial number of driftwood logs. She randomly chooses 30 logs and takes core samples from those logs.

Use the following State whether the data are best described as a population or a sample. -A football fan recorded the number of rushing yards for all NFL running backs who played last season.

Association implies causation.

In elementary school (Grades 1 through 6) there is a strong association between a child's height and reading ability. What is a possible confounding variable that would help explain this relationship? Explain briefly.

A sample of college age students shows an interesting association between hair length (in inches) and height (also in inches). On average, shorter students tend to have longer hair. What is a possible confounding variable that would help explain this relationship? Explain briefly.