Deck 1: Introduction to Statistics

Question 1

Identify the type of observational study used. A town obtains current employment data by polling 10,000 of its citizens this month.

A) Retrospective
B) Cross-sectional
C) Prospective
D) None of these

Answer 1

B

Question 2

A management survey for a company surveyed 235 employees. 44.7% of the employees surveyed were females. The number of males would be ________.

A) 130
B) 13
C) 105
D) Unable to determine

Answer 2

A

Question 3

A tax auditor selects every 1000th income tax return that is received. Identify which of these types of sampling is used.

A) Systematic
B) Simple Random
C) Convenience
D) Stratified
E) Cluster

Answer 3

A

Question 4

A psychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. She randomly selects 100 students from the 260 business majors and 100
Students from the 180 political science majors. Does this sampling plan result in a random sample? Simple
Random sample? Explain.

A) No; yes. The sample is not random because political science majors have a greater chance of being selected than business majors. It is a simple random sample because all samples of size 200 have the same chance
Of being selected.
B) Yes; no. The sample is random because all students have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample consisting of 50 business
Majors and 150 political science majors.
C) Yes; yes. The sample is random because all students have the same chance of being selected. It is a simple random sample because all samples of size 200 have the same chance of being selected.
D) No; no. The sample is not random because political science majors have a greater chance of being selected than business majors. It is not a simple random sample because some samples are not possible, such as a
Sample consisting of 50 business majors and 150 political science majors.

Question 5

A ________ is the collection of data from every member of the population.

A) sample
B) statistic
C) census
D) placebo

Question 6

Determine whether the given value is a discrete or continuous variable. People are asked to state how many times in the last month they visited their family doctor.

A) Discrete
B) Continuous

Question 7

On a test, 74% of the questions are answered correctly. If 111 questions are correct, how many questions are on the test?

A) 37 questions
B) 67 questions
C) 82 questions
D) 150 questions

Question 8

Determine whether the given value is a statistic or a parameter. Thirty percent of all dog owners poop scoop after their dog.

A) Parameter
B) Statistic

Question 9

Identify which type of sampling is used. The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag.

A) Cluster
B) Simple Random
C) Stratified
D) Systematic
E) Convenience

Question 10

What type of data values are quantitative and the number of values is finite or countable?

A) Categorical
B) Interval
C) Continuous
D) Discrete

Question 11

A ________ is the complete collection of all measurements or data collected, whereas, a ________ is a subcollection of members selected from the complete collection.

A) population; parameter
B) sample; census
C) sample; population
D) population; sample

Question 12

Determine whether the given description corresponds to an experiment or an observational study. A stock analyst selects a stock from a group of twenty for investment by choosing the stock with the greatest earnings
Per share reported for the last quarter.

A) Experiment
B) Observational study

Question 13

There are many potential pitfalls that can cause problems when analyzing data. Which of these choices are not classified as a potential pitfall?

A) Order of survey questions
B) Measured data
C) Self-reported data
D) Nonresponse

Question 14

Determine whether the given value is from a discrete or continuous data set. The time it takes a computer to complete a task.

A) Discrete
B) Continuous

Question 15

Determine which of the four levels of measurement is most appropriate. Students' grades, A, B, or C, on a test.

A) Ratio
B) Ordinal
C) Interval
D) Nominal

Question 16

Researchers collect data by interviewing athletes who have won Olympic gold medals from 1992 to 2016. Identify the type of study.

A) Cross-sectional
B) Prospective
C) Retrospective
D) None of these

Question 17

The four levels of measurement that are commonly used for classifying data are ratio, ________, ________, and ________.

A) nominal; ordinal; categorical
B) normal; ordinal; interval
C) interval; normal; ordinary
D) nominal; ordinal; interval

Question 18

Identify which type of sampling is used. To avoid working late, a quality control analyst simply inspects the first 100 items produced in a day.

A) Convenience
B) Systematic
C) Simple Random
D) Stratified
E) Cluster

Question 19

An education expert is researching teaching methods and wishes to interview teachers from a particular school district. She randomly selects ten schools from the district and interviews all of the teachers at the selected
Schools. Does this sampling plan result in a random sample? Simple random sample? Explain.

A) Yes; no. The sample is random because all teachers have the same chance of being selected. It is not a simple random sample because some samples are not possible, such as a sample that includes teachers
From schools that were not selected.
B) No; no. The sample is not random because teachers in small schools are more likely to be selected than teachers in larger schools. It is not a simple random sample because some samples are not possible, such
As a sample that includes teachers from schools that were not selected.
C) Yes; yes. The sample is random because all teachers have the same chance of being selected. It is a simple random sample because all samples have the same chance of being selected.
D) No; yes. The sample is not random because teachers in small schools are more likely to be selected than teachers in larger schools. It is a simple random sample because all samples have the same chance of being
Selected.

Question 20

Correlation does not imply ________.

A) bias
B) linearity
C) significance
D) causation

Question 21

Identify which type of sampling is used. A research team wants to study the demographics of college students in the United States using proportionate samples of students in majors reflecting actual U.S. percentages.

A) Convenience
B) Cluster
C) Simple random
D) Systematic
E) Stratified

Question 22

A marijuana survey included 1610 responses from a list of approximately 241,500,000 adults in the United States from which every 150,000th name was surveyed. Identify which of these types of sampling is used:

A) Convenience
B) Stratified
C) Systematic
D) Simple random
E) Cluster

Question 23

The similarity between an ordinal level of measurement and an interval level of measurement is that ________.

A) differences between data values cannot be determined or are meaningless
B) both can be arranged in some order
C) neither can be arranged in some order
D) differences between data values can be determined and are meaningful

Question 24

Determine which level of measurement is appropriate. Salaries of college professors.

A) Nominal
B) Ratio
C) Interval
D) Ordinal

Question 25

Which type of experiment separates subjects into groups that are similar but differ in ways that might affect the outcome of the experiment?

A) Rigorously controlled design
B) Randomized block design
C) Completely randomized design
D) Matched pairs design

Question 26

Identify the type of study used. A town obtains current employment data by polling 10,000 of its citizens this month.

A) Retrospective
B) Prospective
C) Cross-sectional
D) None of these

Question 27

Identify which type of sampling is used. A pollster uses a computer to generate 500 random numbers, then interviews the voters corresponding to those numbers.

A) Systematic
B) Cluster
C) Stratified
D) Convenience
E) Random

Question 28

A gardener has 75 clients, 45% of whom are businesses. Find the number of business clients.

A) 73 clients
B) 41 clients
C) 34 clients
D) 36 clients

Question 29

The good design of experiments includes blinding, ________, and ________.

A) replication; randomization
B) replication; experimentation
C) internalization; randomization
D) replication; voluntary response samples

Question 30

A marketing firm does a survey to find out how many people use a product. Of the one hundred people contacted, fifteen said they use the product. Identify the type of study used.

A) Experiment
B) Observational study

Question 31

In a cross-sectional study, data are ________.

A) collected from a past time period
B) collected in the future from groups that share common factors
C) observed, measured, and collected at one point of time
D) observed, measure, and collected over a period of time

Question 32

Determine whether the given description corresponds to an observational study or an experiment. A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.

A) Experiment
B) Observational study

Question 33

Which of the following is an inappropriate way to deal with missing data?

A) Delete cases with missing data
B) Determine if missing values are random
C) Ignore missing data
D) Substitute missing values

Question 34

Which of the following does not apply to the ratio level of measurement?

A) There is a natural zero starting point
B) Differences between data values can be found and are meaningful
C) Cannot be arranged in order
D) Can be arranged in order

Question 35

Determine whether the given description corresponds to an observational study or an experiment. A doctor gives a new medication to half of his patients with the flu and a placebo to the other half of his patients with the
Flu)

A) Experiment
B) Observational study

Question 36

Determine which of the four levels of measurement is most appropriate. Students' grades of A, B, or C, on a test.

A) Ratio
B) Nominal
C) Interval
D) Ordinal

Question 37

Identify which type of sampling is used. A tax auditor selects every 1000th income tax return that is received.

A) Stratified
B) Systematic
C) Random
D) Convenience
E) Cluster

Question 38

Determine which of the four levels of measurement is most appropriate. Level of satisfaction of survey respondents.

A) Nominal
B) Ordinal
C) Interval
D) Ratio

Question 39

Determine whether the given value is a statistic or a parameter. After taking the first exam, 15 of the students dropped the class.

A) Parameter
B) Statistic

Question 40

Determine which level of measurement is appropriate. A sample of children's balls are classified from softest to hardest.

A) Ratio
B) Nominal
C) Interval
D) Ordinal

Question 41

At a school there are two different math classes for children of the same age. The two classes have different
teachers. The school principal is interested in gauging the effectiveness of two different teaching methods and
asks each teacher to try one of the methods. At the end of the semester both classes are given the same test and
the results are compared. In this experiment, what is the variable of interest? Give some examples of variables
which could be confounding variables.

Question 42

The table shows the weights (in pounds) and monthly incomes (in dollars) of nine randomly selected women
between the ages of 18 and 65. If we use statistical methods to conclude that there is a correlation (or relationship or association) between the weights of
women and their monthly incomes, can we conclude that by increasing her weight a woman can increase her monthly
income?

Question 43

Explain what is meant by the term "confounding," and give an example of an experiment in which confounding
is likely to be a problem.

Question 44

A coach uses a new technique in training middle distance runners. The times, in seconds, for 8 different athletes
to run 800 meters before and after this training are shown below. Does the conclusion that the technique is effective appear to be supported with statistical significance? Does the
conclusion that the technique is effective appear to have practical significance?

Question 45

Form a conclusion about statistical significance. Do not make any formal calculations. Either use the results
provided or make subjective judgments about the results.
Last year, the average math SAT score for students at one school was 475. The headmaster introduced new
teaching methods hoping to improve scores. This year, the mean math SAT score for a sample of students was
481. Is there statistically significant evidence that the new teaching method is effective? If the teaching method
had no effect, there would be roughly a 3 in 10 chance of seeing such an increase. Does the result have statistical
significance? Why or why not? Does the result have practical significance?

Question 46

Distinguish between categorical and quantitative data. Give an example of each.

Question 47

A teacher was interested in knowing how much tax people pay in the United States. She selected a simple
random sample of her friends and asked them about their taxes. Is this sample likely to be representative of all
adults in the United States?

Question 48

Subscribers of the women's magazine Cosmopolitan are asked to participate in a survey about preferred cereals
for breakfast. Are the results likely to be representative of all women? Of all subscribers of Cosmopolitan? Why
or why not?

Question 49

Identify the sample and population. Also, determine whether the sample is likely to be representative of the
population. A study is interested in whether men and women are equally likely to vote Democratic, Republican
or Independent or not vote in a presidential election. Results were polled through a popular news website.

Question 50

Explain the difference between stratified and cluster sampling.

Question 51

A lawyer surveyed a simple random sample of his colleagues and asked them whether they were left-handed
or right-handed. Is this convenience sample likely to provide results typical of all adults in the United States?
Do convenience samples in general provide good results?

Question 52

Why do you think that cluster sampling is frequently used in practice?

Question 53

Would an observational study or an experiment be more appropriate to investigate the effects on fertilizer on
plant growth? Explain.

Question 54

"38% of adults in the United States regularly visit a doctor". This conclusion was reached by a college student
after she had questioned 520 randomly selected members of her college. What is wrong with her conclusion?

Question 55

Why is cluster sampling frequently used in practice?

Question 56

Use critical thinking to develop an alternative conclusion. A study shows that the number of reported sexually
transmitted diseases was significantly higher for high schools that offered courses in sex education than for high
schools that did not. Conclusion: The introduction of sex education courses at the high school level has resulted
in increased promiscuity among teens.

Question 57

Explain why using self-reported data instead of measured data is a potential pitfall in data collection. Be sure to
include an example.

Question 58

Would an observational study or an experiment be more appropriate to investigate the effects on humans of a
substance known to be toxic? Explain.

Question 59

Identify the sample and population. Also, determine whether the sample is likely to be representative of the
population. An employee at the local ice cream parlor asks three customers if they like chocolate ice cream.

Question 60

Given the data in the table, what issue can be addressed by conducting a statistical analysis of the values?
Amounts of Saturated Fat (in grams) in Two-Once Regular and Low-Fat Muffins

Question 61

Use the data in the table to answer the question. The x-values are amounts of saturated fat (in grams) in various
regular two-ounce muffins. The y-values are amounts of saturated fat (in grams) in various "low fat"
two-ounce muffins. The measured amounts of saturated fat were supplied by the producers of the muffins. Is there an incentive for
producers to report values that are not accurate?

Question 62

"7 out of 10 dentists recommend Brand X toothpaste". This finding is based on the results of a survey of 10
randomly selected dentists. What is wrong with this survey?

Question 63

A researcher investigated whether following a vegetarian diet could help to reduce blood pressure. For a
sample of 85 people who followed a vegetarian diet for 4 months, the mean systolic blood pressure was
124 mmHg and for a sample of 75 people who followed a nonvegetarian diet for 4 months, the mean systolic
blood pressure was 138 mmHg. Methods of statistics show that if a vegetarian diet had no effect on blood
pressure, there would be less than 1 chance in a 100 of getting these results. Does the result have statistical
significance? Why or why not? Does the result have practical significance?

Question 64

A questionnaire is sent to 10,000 persons. 5,000 responded to the questionnaire. 3,000 of the respondents say that
they "love chocolate ice cream". We conclude that 60% of people love chocolate ice cream. What is wrong with
this survey?

Question 65

Use the data in the table to answer the question. The x-values are amounts of saturated fat (in grams) in various
regular two-ounce muffins. The y-values are amounts of saturated fat (in grams) in various "low fat"
two-ounce muffins. Is each x-value matched with a corresponding y-value? That is, is each x-value associated with the
corresponding y-value in some meaningful way? If the x- and y-values are not matched, does it make sense to
use the difference between each x-value and the y-value that is in the same column?

Question 66

In a random sample of 160 women, 78% favored stricter gun control laws. In a random sample of 220 men, 61%
favored stricter gun control laws. Is there statistically significant evidence that a larger proportion of women
than men favor stricter gun control laws?

Question 67

An airline company advertises that 100% of their flights are on time after checking 5 randomly selected flights
and finding that these 5 were on time. What is wrong with their claim?

Question 68

"38% of adults in the United States regularly visit a doctor". This conclusion was reached by a college student
after she had questioned 520 randomly selected members of her college. What is wrong with her survey?

Question 69

A manufacturer of laptop computers claims that only 1% of their computers are defective. In a sample of 600
computers, it was found that 3% were defective. If the proportion of defectives were really only 1%, there would
be less than 1 chance in 1000 of getting such a large proportion of defective laptops in the sample. Is there
statistically significant evidence against the manufacturer's claim? Why or why not?

Question 70

A researcher published this survey result: "74% of people would be willing to spend 10 percent more for energy
from a non-polluting source". The survey question was announced on a national radio show and 1,200 listeners
responded by calling in. What is wrong with this survey?

Question 71

You plan to make a survey of 200 people. The plan is to talk to every 10th person coming out of the school
library. Is there a problem with your plan?

Question 72

In a study of headache patients, every one of the study subjects with a headache was found to be improved after
taking a week off of work. Conclusion: Taking time off work cures headaches.

Question 73

The table shows the weights (in pounds) and monthly incomes (in dollars) of nine randomly selected women
between the ages of 18 and 65. Assume that the x-values are the weights and the y-values are the monthly
incomes.
What i ssue can be addressed by conducting a statistical analysis of the values?

Question 74

Use the data in the table to answer the question. The x-values are amounts of saturated fat (in grams) in various
regular two-ounce muffins. The y-values are amounts of saturated fat (in grams) in various "low fat"
two-ounce muffins. Note that the table lists measured amounts of saturated fat in two different types of muffin. Given these data,
what issue can be addressed by conducting a statistical analysis of the values?

Question 75

Last year, the average math SAT score for students at one school was 475. The headmaster introduced new
teaching methods hoping to improve scores. This year, the mean math SAT score for a sample of students was
481. Is there statistically significant evidence that the new teaching method is effective? If the teaching method
had no effect, there would be roughly a 3 in 10 chance of seeing such an increase. Does the result have
statistical significance? Why or why not? Does the result have practical significance?

Question 76

The table shows the weights (in pounds) and monthly incomes (in dollars) of nine randomly selected women
between the ages of 18 and 65. Assume that the x-values are the weights and the y-values are the monthly
incomes.
Are the x -values matched with the corresponding y-values? That is, is each x-value associated with the
corresponding y-value in some meaningful way? If the x- and y-values are matched, does it make sense to use
the difference between each x-value and the y-value that is in the same column? Why or why not?

Question 77

A study shows that adults who work at their desk all day weigh more than those who do not. Conclusion: Desk
jobs cause people to gain weight.

Question 78

Charlie's teacher claims that he does not study and just guesses on exams. On an exam with 201 true-false
questions, Charlie answered 53.7% of the questions correctly. Calculations using these results show that if he
were really just guessing, there would be roughly 1 chance in 7 that he would do this well. Is there statistically
significant evidence against the teacher's claim that Charlie is just guessing? Why or why not?

Question 79

The table shows the weights (in pounds) and monthly incomes (in dollars) of nine randomly selected women
between the ages of 18 and 65. Assume that the x-values are the weights and the y-values are the monthly
incomes.
If we use statist ical methods to conclude that there is a correlation (or relationship or association) between the
weights of women and their monthly incomes, can we conclude that by increasing her weight a woman can
increase her monthly income?

Question 80

The table shows the weights, in pounds, of seven subjects before and after following a particular diet for two
months. Assume that the x-values are the weights before the diet and the y-values are the weights after the
diet. Are the x-values matched with the corresponding y-values? That is, is each x-value associated with the
corresponding y-value in some meaningful way? If the x- and y-values are matched, does it make sense to use
the difference between each x-value and the y-value that is in the same column? Why or why not?