Deck 1: Introduction to Data

Question 1

Determine if the following scenario is an observational study or a controlled experiment and explain your reasoning. A school teacher is interested in determining whether students who take multiple choice tests do better than students who take true/false tests. She has been giving multiple choice tests since she started teaching and is wondering if she should change her testing method. She randomly assigns half of her students to take a multiple choice test about grammar rules, and the other half to take a true/false test about grammar rules. She compares the test scores of the students in each group.

Answer 1

This is a controlled experiment because the students are randomly assigned to the treatment group (true/false test) and the control group (multiple choice test).

Question 2

According to the following two-way table, what percent of people in the sample eat breakfast?

Answer 2

Question 3

Researchers conducted a study and determined that coworkers who socialize outside of work are more productive than coworkers who do not. Can we conclude that socializing outside of work causes coworkers to be more productive? Explain your reasoning.

Answer 3

No, this is an observational study and we cannot conclude causation.

Question 4

Researchers conducted an experiment to determine if having a dog day on college campuses during final exam week lowers students' stress levels. A dog day is when dogs from a local animal shelter are brought onto campus for students to play and interact with. What are the treatment and outcome variables for this experiment?

Question 5

Use the following information for following questions:
A group of 500 patients who suffer from severe migraines were asked to participate in a study to
determine the effectiveness of a new medication. The patients were randomly divided into two
groups, one that was given the actual medication, and one that received a placebo pill. A good
outcome was defined as a reduction in the number of migraines during a month's time. The
results of the study are below.
Can we conclude that the reduction of migraines was caused by the new medication? Explain your reasoning.

Question 6

In a recent study of 1200 adult smokers, 125 out of the 560 males in the study said they were interested in joining a help group to quit smoking. What percent of the study's participants were female?

Question 7

Give an example of one categorical variable and one numerical variable.

Question 8

Determine if the following scenario is an observational study or a controlled experiment and explain your reasoning. A doctor is interested in determining whether a certain medication is effective at treating abdominal pain. He reviews his patients' medical records and finds that a higher proportion of people who took the medication fewer abdominal pain symptoms than those who did not take the medication.

Question 9

What types of variables are represented in a two-way table? Give an example.

Question 10

In a recent survey at UCLA, some incoming freshmen students were asked if they planned to take more than one math class before they graduated. What is the population of interest here and what is the sample?

Question 11

In the following table, gender is a categorical variable. Give one possible way the variable could have been coded.

Question 12

A college is offering a new free tutoring program for students in an introductory statistics class. The school wants to know if this new program improves students' test scores on their midterms and final exams. What variable could be a possible confounding factor in determining why students' scores improved or not?

Question 13

In a recent study of 1200 adult smokers, 125 out of the 560 males in the study said they were interested in joining a help group to quit smoking. What percent of males are interested in joining this group?

Question 14

Use the following information for following questions:
A group of 500 patients who suffer from severe migraines were asked to participate in a study to
determine the effectiveness of a new medication. The patients were randomly divided into two
groups, one that was given the actual medication, and one that received a placebo pill. A good
outcome was defined as a reduction in the number of migraines during a month's time. The
results of the study are below.
Was the new medication effective for reducing migraines? Explain your reasoning and include any calculations.

Question 15

Determine whether the following data table is stacked or unstacked and explain your reasoning.

Question 16

Give an example of how anecdotal evidence can be used to persuade consumers to purchase a product.

Question 17

Use the following information for following questions:
A group of 500 patients who suffer from severe migraines were asked to participate in a study to
determine the effectiveness of a new medication. The patients were randomly divided into two
groups, one that was given the actual medication, and one that received a placebo pill. A good
outcome was defined as a reduction in the number of migraines during a month's time. The
results of the study are below.
Approximately what percent of patients who took the medication had a reduction in the amount of migraines?

Question 18

What is the difference between a blind and a double blind study? Which is most ideal?

Question 19

According to the following two-way table, why are percentages more useful than counts to compare the amount of males and females who eat breakfast?

Question 20

Give an example of how data could be collected about you on a daily basis.

Question 21

A two-way table could be used for which of the following pairs of variables?

A)Age and height
B)Gender and age
C)Gender and favorite class
D)Age and favorite class

Question 22

Use the following information for following questions:
A group of 500 patients who suffer from skin cancer were asked to participate in a study to
determine the effectiveness of a new medication. The patients were randomly divided into two
groups, one that was given the actual medication, and one that received a placebo pill. A good
outcome was defined as the cancer being in remission after 6 months of treatment. The results of
the study are below.
Approximately what percent of patients who took the medication had cancer remission?

A)48%
B)50%
C)58%
D)67%

Question 23

Researchers conducted a study and determined that students who carpool have less friends than students who ride the bus to school. Can we conclude that carpooling causes students to have less friends?

A)Yes, this is an observational study and we can conclude causation.
B)Yes, this is an experiment and we can conclude causation.
C)No, this is an observational study and we cannot conclude causation.
D)No, this is an experiment and we cannot conclude causation.

Question 24

Data can be defined as numbers in context. Suppose you are given the following set of numbers: What additional information would allow you to define these numbers as data?

A)We need to know where these numbers were collected.
B)We need to know who collected these numbers.
C)Units of measurement.This could represent the ages of six high school students.
D)Units of measurement.This could represent the ages of six college students.

Question 25

Researchers conducted an experiment to determine if riding a bike to school improves attention span. What are the treatment and outcome variables?

A)The treatment variable is riding a bike to school.The outcome variable is whether or not the child rode a bike to school.
B)The treatment variable is riding a bike to school.The outcome variable is the child's attention span.
C)The treatment variable is attention span.The outcome variable is whether or not the child rode a bike to school.
D)The treatment variable is attention span.The outcome variable is the child's attention span score.

Question 26

In a recent high school poll, the principal asked if students were satisfied with the amount of after-school activities offered. What is the population of interest here?

A)All students who attend the school.
B)All students who participated in the poll.
C)All students who are satisfied with the amount of after-school activities that are offered.
D)All students who are not satisfied with the amount of after-school activities that are offered.

Question 27

According to the following two-way table, what percent of people in the sample take naps?

A)25%
B)35%
C)55%
D)60%

Question 28

Use the following information for following questions:
A group of 500 patients who suffer from skin cancer were asked to participate in a study to
determine the effectiveness of a new medication. The patients were randomly divided into two
groups, one that was given the actual medication, and one that received a placebo pill. A good
outcome was defined as the cancer being in remission after 6 months of treatment. The results of
the study are below.
Was the new medication effective for cancer remission?

A)Yes, a higher percent of patients who took the medication had cancer remissions than the patients who took the placebo.
B)Yes, both groups had more patients with cancer remissions.
C)No, the patients who took the placebo also had cancer remissions.
D)No, this was not a controlled experiment.

Question 29

According to the following data table, which variable(s) is(are) categorical?

A)Gender
B)Gender and ethnicity
C)Gender, shoe size, and ethnicity
D)None are categorical because there are only numbers in the table

Question 30

According to the following two-way table, why are percentages more useful than counts to compare the amount of males and females who take naps?

A)There are more males than females in the sample.
B)There are more people who take naps than people who do not in the sample.
C)You should only use counts in a two-way table.
D)You should only use percentages in a two-way table.

Question 31

In a study of 1350 elementary school children, 118 out of the 615 girls in the study said they want to be a teacher when they grow up. What percent of girls want to be a teacher when they grow up?

A)8.7%
B)19.2%
C)45.6%
D)80.8%

Question 32

The following data table is organized using which method?

A)This is stacked data because the ages are separated by groups (in this case, gender).
B)This is stacked data because each row represents one person.
C)This is unstacked data because the ages are separated by groups (in this case, gender).
D)This is unstacked data because each row represents one person.

Question 33

Use the following information for following questions:
A group of 500 patients who suffer from skin cancer were asked to participate in a study to
determine the effectiveness of a new medication. The patients were randomly divided into two
groups, one that was given the actual medication, and one that received a placebo pill. A good
outcome was defined as the cancer being in remission after 6 months of treatment. The results of
the study are below.
Can we conclude that the cancer remissions were caused by the new medication?

A)Yes, this is a controlled experiment.Since a higher percent of patients who took the medication had cancer remissions, we can conclude causation.
B)Yes, this is a controlled experiment.We can always conclude causation with a controlled experiment.
C)No, even though this is a controlled experiment, there was no difference between the treatment and control groups, so we cannot conclude causation.
D)No, even though this is a controlled experiment, there might be a confounding factor since the placebo group had cancer remissions too.

Question 34

Determine which of the following five variables are numerical and which are categorical. age, gender, height, favorite candy, eye color

A)Age, height, and favorite candy are numerical variables.Gender and ethnicity are categorical variables.
B)Age and height are numerical variables.Gender, favorite candy, and eye color are categorical variables.
C)All of the variables are categorical.
D)All of the variables are numerical.

Question 35

Coconut oil has become quite popular in recent years. People who use coconut oil claim it helps with hair care, skin care, stress relief, weight loss, and a boosted immune system. Can we conclude that the use of coconut oil causes these health benefits?

A)Yes, the claims are anecdotes and give us a good comparison group to find health differences.
B)No, the claims are anecdotes and do not give us a true comparison group to find health differences.
C)Yes, the claims are true stories, so we do have evidence of the health benefits.
D)No, the claims are lies, so we do not have evidence of the health benefits.

Question 36

What does it mean for an experiment to be random?

A)Assignment into the control and treatment groups is determined by chance.
B)Assignment into the control and treatment groups is determined by the researcher.
C)Assignment into the control and treatment groups is determined by the participants.
D)Assignment into the control and treatment groups is determined by a person who is not involved in the research.

Question 37

In a study of 1350 elementary school children, 118 out of the 615 girls in the study said they want to be a teacher when they grow up. What percent of the study's participants were boys?

A)19.2%
B)45.6%
C)54.4%
D)83.7%

Question 38

Determine if the following scenario is an observational study or a controlled experiment. A doctor is interested in determining whether a certain medication reduces migraines. She randomly selects 100 people for his study - 50 who will take the medication, and 50 who will take a placebo. The patients are examined once a week for six weeks.

A)Observational study
B)Controlled experiment
C)Neither

Question 39

Determine if the following scenario is an observational study or a controlled experiment. A doctor is interested in determining whether a certain medication reduces migraines. She reviews her patients' medical records and finds that a higher proportion of people who take the medication have fewer migraines than those who did not take the medication.

A)Observational study
B)Controlled experiment
C)Neither

Question 40

A gym is offering a new 6-week diet plan for its members. Members who sign up for the program are weighed and measured once a week for the duration of the program. The owners of the gym want to know if the diet plan actually helps people lose weight. What variable could be a possible confounding factor in determining the cause of weight loss?

A)The person's education level.
B)The person's marital status.
C)The person's social life.
D)The person's exercise routine.

Question 41

According to the following data table, which variable(s) is(are) categorical?

A)None are categorical because there are only numbers in the table
B)Age, gender, and ethnicity
C)Gender and ethnicity
D)Gender

Question 42

In a study of 1200 adults, 480 out of the 630 women in the study said they attended a state college or university. What percent of women attended a state college or university?

A)40%
B)47.5%
C)52.5%
D)76.2%

Question 43

What does it mean for an experiment to be double-blinded?

A)The researcher does not know which participants are in the treatment and control groups.
B)The participants do not know who is in the treatment and control groups.
C)Neither the researcher nor the participants know who is in the treatment and control groups.
D)The researcher and the participants know which group they are in because it is unethical to keep this information from them.

Question 44

Data can be defined as numbers in context. Suppose you are given the following set of numbers: What additional information would allow you to define these numbers as data?

A)Units of measurement.This could represent the heights of six 5-year-olds, in meters.
B)Units of measurement.This could represent the heights of six 20-year-olds, in meters.
C)We need to know where these numbers were collected.
D)We need to know who collected these numbers.

Question 45

Use the following information for following questions:
A group of 500 patients who suffer from hypothyroidism, a condition in which your thyroid does
not produce enough of certain hormones, were asked to participate in a study to determine
the effectiveness of a new medication. The patients were randomly divided into two groups,
one that was given the actual medication, and one that received a placebo pill. The results of
the study are below.
What percent of patients who took the medication had improved symptoms?

A)41%
B)54%
C)65.2%
D)75.9%

Question 46

A gym is offering a new 6-week weight loss exercise program for its members. Members who sign up for the program are weighed and measured once a week for the duration of the program. The owners of the gym want to know if the weight loss program actually helps people lose weight. What variable could be a possible confounding factor in determining the cause of weight loss?

A)The person's commitment to the program.
B)The person's marital status.
C)The person's family structure.
D)The person's diet.

Question 47

Use the following information for following questions:
A group of 500 patients who suffer from hypothyroidism, a condition in which your thyroid does
not produce enough of certain hormones, were asked to participate in a study to determine
the effectiveness of a new medication. The patients were randomly divided into two groups,
one that was given the actual medication, and one that received a placebo pill. The results of
the study are below.
Can we conclude that the improved symptoms were caused by the new medication?

A)Yes, this is a controlled experiment.Since a higher percent of patients who took the medication had improved symptoms, we can conclude causation.
B)Yes, this is a controlled experiment.We can always conclude causation with a controlled experiment.
C)No, even though this is a controlled experiment, there was no difference between the treatment and control groups, so we cannot conclude causation.
D)No, even though this is a controlled experiment, there might be a confounding factor since the placebo group had improved symptoms too.

Question 48

Researchers conducted an experiment to determine if children who participate in a new after-school tutoring program do better on state-mandated tests than children who do not attend the program. What are the treatment and outcome variables?

A)The treatment variable is participation in the after-school program.The outcome variable is whether or not a child attended.
B)The treatment variable is participation in the after-school program.The outcome variable is the test score on the state-mandated test.
C)The treatment variable is the state-mandated test.The outcome variable is the participation in the after-school program.
D)The treatment variable is the state-mandated test.The outcome variable is the test score on the state-mandated test.

Question 49

According to the following two-way table, why are percentages more useful than counts to compare pet preferences between males and females?

A)There are more males than females in the sample.
B)There are more people who prefer dogs than cats in the sample.
C)You should only use counts in a two-way table.
D)You should only use percentages in a two-way table.

Question 50

Use the following information for following questions:
A group of 500 patients who suffer from hypothyroidism, a condition in which your thyroid does
not produce enough of certain hormones, were asked to participate in a study to determine
the effectiveness of a new medication. The patients were randomly divided into two groups,
one that was given the actual medication, and one that received a placebo pill. The results of
the study are below.
Was the new medication effective in treating hypothyroidism?

A)Yes, a higher percent of patients who took the medication had improved symptoms than the patients who took the placebo.
B)Yes, both groups had more patients with improved symptoms.
C)No, the patients who took the placebo also had improved symptoms.
D)No, this was not a controlled experiment.

Question 51

In Los Angeles, juice cleansing is very popular. Some people have claimed that the cleanses are beneficial for weight loss, body detoxification, and treatment and prevention of illnesses. Can we conclude that juice cleansing causes these health benefits?

A)Yes, the claims are true stories, so we do have evidence of the health benefits.
B)No, the claims are lies, so we do not have evidence of the health benefits.
C)Yes, the claims are anecdotes and give us a good comparison group to find health differences.
D)No, the claims are anecdotes and do not give us a true comparison group to find health differences.

Question 52

In a recent school poll, the administrators asked if students were satisfied with the school's course offerings. What is the population of interest here?

A)All students who are satisfied with the course offerings.
B)All students who are not satisfied with the course offerings.
C)All students who attend the school.
D)All students who participated in the poll.

Question 53

According to the following two-way table, what percent of people in the sample prefer dogs?

A) 25%
B) 35%
C) 40%
D) 65%

Question 54

Determine if the following scenario is an observational study or a controlled experiment. A doctor is interested in determining whether a certain medication increases the risk of high blood pressure. He randomly selects 100 people for his study - 50 who will take the medication, and 50 who will take a placebo. He checks the patients' blood pressures weekly for six months.

A)Observational study
B)Controlled experiment
C)Neither

Question 55

The following data table is organized using which method?

A)This is stacked data because the ages are separated by groups (in this case, gender).
B)This is stacked data because each row represents one person.
C)This is unstacked data because the ages are separated by groups (in this case, gender).
D)This is unstacked data because each row represents one person.

Question 56

Researchers conducted a study and determined that students who participate in sports are happier than students who do not. Can we conclude that participating in sports makes students happier?

A)Yes, this is an observational study and we can conclude causation.
B)Yes, this is an experiment and we can conclude causation.
C)No, this is an observational study and we cannot conclude causation.
D)No, this is an experiment and we cannot conclude causation.

Question 57

In a study of 1200 adults, 480 out of the 630 women in the study said they attended a state college or university. What percent of the study's participants were women?

A)40%
B)47.5%
C)52.5%
D)76.2%

Question 58

Determine which of the following five variables are numerical and which are categorical. age, gender, weight, ethnicity, favorite math class

A)All of the variables are categorical.
B)All of the variables are numerical.
C)Age, weight, and favorite math class are numerical variables.Gender and ethnicity are categorical variables.
D)Age and weight are numerical variables.Gender, ethnicity, and favorite math class are categorical variables.

Question 59

Determine if the following scenario is an observational study or a controlled experiment. A doctor is interested in determining whether a certain medication increases the risk of high blood pressure. He reviews his patients' medical records and finds that a higher proportion of people who take the medication are suffering from high blood pressure.

A)Observational study
B)Controlled experiment
C)Neither

Question 60

A two-way table is useful for describing which types of variables?

A)Two numerical variables.
B)Two categorical variables.
C)One numerical variable.
D)One numerical variable and one categorical variable.