Deck 1: Collecting Data

Question 1

Use the following
A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative.
-Type of college: Private or Public college

Answer 1

Categorical

Question 2

Use the following
A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative.
-Tuition: in thousands of dollars

Answer 2

Quantitative

Question 3

Use the following
A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative.
-State: the state in which the college is located

Answer 3

Categorical

Question 4

Use the following
A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative.
-Zip Code: the zip code of the part of the country in which the college is located

Question 5

Use the following
A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative.
-Enrollment: the number of students enrolled at the college

Question 6

Use the following
A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative.
-Student-Faculty Ratio: the number of students divided by the number of faculty

Question 7

Use the following
A high school senior is collecting data on the colleges in which she is interested. Identify the variables as either categorical or quantitative.
-Graduation Rate: as a percentage

Question 8

What are the cases in the high school senior's dataset?

Question 9

Refer to the variables collected by the high school senior looking at colleges. Identify a question we might ask about any one of these individual variables.

Question 10

Refer to the variables collected by the high school senior looking at colleges. Identify a question that we might ask about relationships between any two (or more) of these variables.

Question 11

Use the following to
A realtor's website provides information on area homes that are for sale. Identify each of the variables as either categorical or quantitative.
-List Price: amount, in thousands of dollars, for which the house is being sold

Question 12

Use the following to
A realtor's website provides information on area homes that are for sale. Identify each of the variables as either categorical or quantitative.
-School District: the school district in which the home is located

Question 13

Use the following to
A realtor's website provides information on area homes that are for sale. Identify each of the variables as either categorical or quantitative.
-Size: in square feet

Question 14

Use the following to
A realtor's website provides information on area homes that are for sale. Identify each of the variables as either categorical or quantitative.
-Style: the style of home (ranch, Cape Cod, Victorian, etc.)

Question 15

What are the cases in the realtor's dataset?

Question 16

Refer to the variables provided by the realtor. Identify a question we might ask about any one of these individual variables.

Question 17

Refer to the variables provided by the realtor. Identify a question that we might ask about relationships between any two (or more) of these variables.

Question 18

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 are the cases in this datatset?

Question 19

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 from this dataset is displayed? Is it categorical or quantitative?

Question 20

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.

-Data from the state of Connecticut were used to determine that 43.4% of state residents had a college degree. What were the cases from Connecticut used to arrive at this figure?

Question 21

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?

Question 22

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

Question 23

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.

Question 24

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.

Question 25

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.

Question 26

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.

Question 27

A population includes all individuals or objects of interest.

Question 28

A population is a subset of the sample.

Question 29

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

Question 30

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.

Question 31

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.

Question 32

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.

Question 33

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.

Question 34

Association implies causation.

Question 35

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.

Question 36

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.

Question 37

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?

Question 38

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.

Question 39

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.

Question 40

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.

Question 41

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.
-Is a control group used in this experiment? If so, which group is the control group?

Question 42

Use the following
A tree enthusiast is interested in estimating the typical length of oak tree leaves. He chooses 30 leaves from the oak tree in his backyard.
-What is the sample in this situation?

Question 43

Use the following
A tree enthusiast is interested in estimating the typical length of oak tree leaves. He chooses 30 leaves from the oak tree in his backyard.
-What is the population in which the tree enthusiast is interested?

Question 44

Use the following
A tree enthusiast is interested in estimating the typical length of oak tree leaves. He chooses 30 leaves from the oak tree in his backyard.
-Is this a biased sampling strategy? If so, identify a population that we can generalize to, given our sample.

Question 45

Use the following
In each situation, indicate whether the method of data collection is biased. If it is, briefly explain why.
-Ask the students at the gym on a Tuesday afternoon how many hours a week they work out to estimate the average amount of time students at the university work out.

Question 46

Use the following
In each situation, indicate whether the method of data collection is biased. If it is, briefly explain why.
-A professor asks her class of first year students if any of them consumed alcohol over the weekend.

Question 47

Use the following
In each situation, indicate whether the method of data collection is biased. If it is, briefly explain why.
-A campus bookstore is holding a drawing to give away five free textbooks (one per student). Students enter the contest by writing their name and contact information on an index card. The index cards were placed in a bowl, thoroughly mixed around, and five cards were selected. Those five students were contacted and received their free textbook.

Question 48

Use the following
In each situation, indicate whether the method of data collection is biased. If it is, briefly explain why.
-A professor is considering a new textbook for her introductory statistics class. She wants to choose a book that emphasizes graphing data. A book that she is considering has 530 pages. To estimate the proportion of pages in the book that have displays of data, she randomly generates 20 numbers between 1 and 530. She then records whether or not each selected page contains displays of data.

Question 49

Use the following
In each situation, indicate whether the method of data collection is biased. If it is, briefly explain why.
-A reporter from the campus newspaper is writing an article about student opinions on Greek organizations (sororities and fraternities). For his article, he visits all of the Greek houses on campus and interviews a random sample of residents of each house.

Question 50

Use the following
Identify whether each of the following scenarios describe a randomized comparative experiment or a matched pairs experiment.
-To study the impact of texting while driving, researchers have students drive around an obstacle course twice, once while texting and once without texting (the order of which was randomized). Their score for each turn is the number of obstacles they successfully maneuvered around.

Question 51

Use the following
Identify whether each of the following scenarios describe a randomized comparative experiment or a matched pairs experiment.

-Studies have shown that multi-tasking typically results in lower productivity. However, some people believe that individuals who play video games are better at multi-tasking. To investigate this, 28 video game players were randomly assigned to one of two groups. One group was assigned to play a video game that involved driving a car around a track. The other group was assigned to play the same video game while simultaneously answering unrelated trivia questions over the phone.

Question 52

Use the following
Identify whether each of the following scenarios describe a randomized comparative experiment or a matched pairs experiment.
-To study the effect of classical music on concentration, 26 math majors were assigned at random into two groups. Subjects in one group listened to classical music while trying to solve a hard Sudoku puzzle, while the subjects in the other group solved the same puzzle in a silent room. The time it took each student to finish was recorded.

Question 53

On their website, the makers of Cold-EEZE lozenges provide links to studies done to demonstrate the effectiveness of their product at shortening the duration of the common cold. One study, published in the Annals of Internal Medicine, is described as a "randomized, double-blind, placebo-controlled"
study. Briefly explain what the phrase "randomized, double-blind, placebo-controlled"
means.

Question 54

Is using meditation to relax and clear the mind a natural way to treat insomnia? Design an experiment to investigate this question. Assume that you have 20 individuals who suffer from insomnia available to participate in the study. At the end of two months, you will ask subjects to rate their sleep quality.

Question 55

Use the following to answer questions :
Can people text just as quickly with their off hand as they do their dominant hand? Assume that you have 42 volunteers available to participate in your study, and that the response you will measure is the time it takes to type and send a text message.
-Design a randomized comparative experiment to investigate this question. Be specific about how randomization will be used in your experiment.

Question 56

Use the following to answer questions :
Can people text just as quickly with their off hand as they do their dominant hand? Assume that you have 42 volunteers available to participate in your study, and that the response you will measure is the time it takes to type and send a text message.
-Design a matched pairs experiment to investigate this question. Be specific about how randomization will be used in your experiment.

Question 57

Use the following to answer questions :
The Admissions Office at a small university has developed a new 10-minute video about the university to send to prospective students. Before mass-producing the DVD, they would like to test whether it is more effective than the current video. Suppose that you have 12 high school student volunteers who have agreed to take part in an experiment. The explanatory variable to be studied is the type of video, with two levels OLD and NEW.
-Design a study that could be used in this situation. Give explicit instructions on what the 12 students should do, and be sure to indicate how randomization is used in the study.

Question 58

Use the following to answer questions :
The Admissions Office at a small university has developed a new 10-minute video about the university to send to prospective students. Before mass-producing the DVD, they would like to test whether it is more effective than the current video. Suppose that you have 12 high school student volunteers who have agreed to take part in an experiment. The explanatory variable to be studied is the type of video, with two levels OLD and NEW.
-What specific question would you ask the students to measure as the response variable in this study?

Question 59

Use the following to answer questions :
The Admissions Office at a small university has developed a new 10-minute video about the university to send to prospective students. Before mass-producing the DVD, they would like to test whether it is more effective than the current video. Suppose that you have 12 high school student volunteers who have agreed to take part in an experiment. The explanatory variable to be studied is the type of video, with two levels OLD and NEW.
-What are the cases in your study?

Question 60

Use the following to answer questions :
The Admissions Office at a small university has developed a new 10-minute video about the university to send to prospective students. Before mass-producing the DVD, they would like to test whether it is more effective than the current video. Suppose that you have 12 high school student volunteers who have agreed to take part in an experiment. The explanatory variable to be studied is the type of video, with two levels OLD and NEW.
-Would you describe your study as a randomized comparative experiment, a matched pair experiment, or an observational study? Briefly explain..

Question 61

Use the following to answer questions :
The Admissions Office at a small university has developed a new 10-minute video about the university to send to prospective students. Before mass-producing the DVD, they would like to test whether it is more effective than the current video. Suppose that you have 12 high school student volunteers who have agreed to take part in an experiment. The explanatory variable to be studied is the type of video, with two levels OLD and NEW.
-Explain what it means, in the context of this study, to want the subjects to be "blind."

Question 62

When purchasing some foods, like Jello, at the grocery store, the color of the product typically "matches" the taste. For example, lemon-flavored Jello is yellow, cherry-flavored Jello is red, orange-flavored Jello is orange, and grape-flavored Jello is purple. But, does the color of our food impact the taste that we perceive? Suppose you want to design an experiment to address this question. Note that you can easily make your own "Jello" with simple ingredients that include unflavored gelatin, flavored extracts, and food coloring. Assume that the 30 college students are willing to participate in your study and the response variable is the number of flavors correctly identified.
How would you design a randomized comparative experiment with two groups, each getting a different treatment? Be sure to explain how randomization is used.

Question 63

A group of students were asked to count the number of scars on both of their hands. The number of scars on their dominant hand was compared to the number of scars on their "off" hand. Is this an observational study or a randomized experiment?

A) Observational study
B) Randomized experiment

Question 64

Use the following
A university's Admissions staff sends one of four different representatives to work at college fairs. A study was conducted to evaluate the relative effectiveness of the four representatives. For each college fair over the course of the year, the number of inquiries from students, the type of fair (large or small), the representative who worked at that fair, and the percent of inquiries that resulted in applications were recorded. It was found that one of the representatives was far more effective at getting lots of inquiries.
-What are the cases in this study?

Question 65

Use the following
A university's Admissions staff sends one of four different representatives to work at college fairs. A study was conducted to evaluate the relative effectiveness of the four representatives. For each college fair over the course of the year, the number of inquiries from students, the type of fair (large or small), the representative who worked at that fair, and the percent of inquiries that resulted in applications were recorded. It was found that one of the representatives was far more effective at getting lots of inquiries.
-What are the variables recorded in this study? List them and identify each as either categorical or quantitative.

Question 66

Use the following
A university's Admissions staff sends one of four different representatives to work at college fairs. A study was conducted to evaluate the relative effectiveness of the four representatives. For each college fair over the course of the year, the number of inquiries from students, the type of fair (large or small), the representative who worked at that fair, and the percent of inquiries that resulted in applications were recorded. It was found that one of the representatives was far more effective at getting lots of inquiries.
-Is this an observational study or an experiment? Briefly justify your answer.

Question 67

Use the following
A university's Admissions staff sends one of four different representatives to work at college fairs. A study was conducted to evaluate the relative effectiveness of the four representatives. For each college fair over the course of the year, the number of inquiries from students, the type of fair (large or small), the representative who worked at that fair, and the percent of inquiries that resulted in applications were recorded. It was found that one of the representatives was far more effective at getting lots of inquiries.
-Can we conclude that sending the most effective representative to more college fairs will increase the number of inquiries from those college fairs? Why or why not?

Question 68

A company is interested in redesigning its website, and two possible designs are being considered. The company wants to get input in the form of ratings of the two designs. Design a matched pairs experiment to decide which design gets higher ratings. Fifty volunteers are available to participate.