Picturing Distributions with
Graphs
BPS 7e Chapter 1
© 2014 W. H. Freeman and Company
Individuals and Variables
Airport administrators take a sample of airline baggage and record
the number of bags that weigh more than 75 pounds. What is the
individual?
a)
b)
c)
d)
number of bags weighing more than 75 pounds
average weight of the bags
each piece of baggage
the airport administrators
Individuals and Variables (answer)
Airport administrators take a sample of airline baggage and record
the number of bags that weigh more than 75 pounds. What is the
individual?
a)
b)
c)
d)
number of bags weighing more than 75 pounds
average weight of the bags
each piece of baggage
the airport administrators
Individuals and Variables
In a study of commuting patterns of people in a large metropolitan
area, respondents were asked to report the time they took to travel
to their work on a specific day of the week. What is the individual?
a)
b)
c)
d)
travel time
a person
day of the week
city in which they lived
Individuals and Variables (answer)
In a study of commuting patterns of people in a large metropolitan
area, respondents were asked to report the time they took to travel
to their work on a specific day of the week. What is the individual?
a)
b)
c)
d)
travel time
a person
day of the week
city in which they lived
Individuals vs. Variables
In a study of commuting patterns of people in a large metropolitan
area, respondents were asked to report the time they took to travel
to their work on a specific day of the week. What is the variable of
interest?
a)
b)
c)
d)
travel time
a person
day of the week
city in which they lived
Individuals vs. Variables (answer)
In a study of commuting patterns of people in a large metropolitan
area, respondents were asked to report the time they took to travel
to their work on a specific day of the week. What is the variable of
interest?
a)
b)
c)
d)
travel time
a person
day of the week
city in which they lived
Individuals and Variables
Is the variable “monthly rainfall in Michigan” a categorical or
quantitative variable?
a)
b)
categorical
quantitative
Individuals and Variables (answer)
Is the variable “monthly rainfall in Michigan” a categorical or
quantitative variable?
a)
b)
categorical
quantitative
Individuals and Variables
If we asked people to report their “weight,” would that variable be
considered a categorical or quantitative variable?
a)
b)
categorical
quantitative
Individuals and Variables (answer)
If we asked people to report their “weight,” would that variable be
considered a categorical or quantitative variable?
a)
b)
categorical
quantitative
Individuals and Variables
We ask people whether their weight is underweight, normal,
overweight, or obese. Is this variable categorical or quantitative?
a)
b)
categorical
quantitative
Individuals and Variables (answer)
We ask people whether their weight is underweight, normal,
overweight, or obese. Is this variable categorical or quantitative?
a)
b)
categorical
quantitative
Individuals and Variables
A survey involving 35 questions was given to a sample of 200
students attending a university with an enrollment of 10,000. How
many individuals do the data describe?
a)
b)
c)
d)
35
200
10,000
impossible to say
Individuals and Variables (answer)
A survey involving 35 questions was given to a sample of 200
students attending a university with an enrollment of 10,000. How
many individuals do the data describe?
a)
b)
c)
d)
35
200
10,000
impossible to say
Individuals and Variables
A survey involving 35 questions was given to a sample of 200
students attending a university with an enrollment of 10,000. How
many variables do the data contain?
a)
b)
c)
d)
35
200
35 × 200
35 × 10,000
Individuals and Variables (answer)
A survey involving 35 questions was given to a sample of 200
students attending a university with an enrollment of 10,000. How
many variables do the data contain?
a)
b)
c)
d)
35
200
35 × 200
35 × 10,000
Individuals and Variables
What type of data is produced by the answer choices for this question?
How many times have you
accessed the Internet this
week?
1)
2)
3)
4)
a)
b)
categorical
quantitative
never
once or twice
three or four times
more than four times
Individuals and Variables (answer)
What type of data is produced by the answer choices for this question?
How many times have you
accessed the Internet this
week?
1)
2)
3)
4)
a)
b)
categorical
quantitative
never
once or twice
three or four times
more than four times
Categorical Variables
For data involving answers to the following question, what is the
BEST method of displaying the data?
How many times have you
accessed the Internet this
week?
1)
2)
3)
4)
a)
b)
c)
d)
bar graph
boxplot
histogram
scatterplot
never
once or twice
three or four times
more than four times
Categorical Variables (answer)
For data involving answers to the following question, what is the
BEST method of displaying the data?
How many times have you
accessed the Internet this
week?
1)
2)
3)
4)
a)
b)
c)
d)
bar graph
boxplot
histogram
scatterplot
never
once or twice
three or four times
more than four times
Categorical Variables
The purpose of pie charts and bar charts is to _______________.
a)
b)
c)
d)
hide the data from the audience
impress the audience with interesting colors and shapes
help the audience grasp the distribution of the data quickly
display the distribution of quantitative variables
Categorical Variables (answer)
The purpose of pie charts and bar charts is to _______________.
a)
b)
c)
d)
hide the data from the audience
impress the audience with interesting colors and shapes
help the audience grasp the distribution of the data quickly
display the distribution of quantitative variables
Categorical Variables
Married respondents in a survey were asked how they met their
spouse. According to the bar chart below, how many respondents
met their spouse through a dating service?
a)
b)
c)
d)
2
20
30
70
Categorical Variables (answer)
Married respondents in a survey were asked how they met their
spouse. According to the bar chart below, how many respondents
met their spouse through a dating service?
a)
b)
c)
d)
2
20
30
70
Categorical Variables
Bar graphs are more flexible than pie charts. Both graphs can display
the distribution of a categorical variable, but a bar graph can also
compare any set of quantities that are measured in the same units.
a)
b)
True
False
Categorical Variables (answer)
Bar graphs are more flexible than pie charts. Both graphs can display
the distribution of a categorical variable, but a bar graph can also
compare any set of quantities that are measured in the same units.
a)
b)
True
False
Quantitative Variables
Look at the following histogram of salaries of baseball players.
What shape would you say the data take?
a)
b)
c)
d)
e)
bi-modal
left-skewed
right-skewed
symmetric
uniform
Quantitative Variables (answer)
Look at the following histogram of salaries of baseball players.
What shape would you say the data take?
a)
b)
c)
d)
e)
bi-modal
left-skewed
right-skewed
symmetric
uniform
Quantitative Variables
Look at the following histogram of percent urban population in 50
U.S. states. What shape would you say the data take?
a)
b)
c)
d)
e)
bi-modal
left-skewed
right-skewed
symmetric
uniform
Quantitative Variables (answer)
Look at the following histogram of percent urban population in 50
U.S. states. What shape would you say the data take?
a)
b)
c)
d)
e)
bi-modal
left-skewed
right-skewed
symmetric
uniform
Quantitative Variables
Considering this histogram, about how many students in the survey
paid more than $250 for textbooks?
a)
b)
c)
d)
29
47
52
71
Quantitative Variables (answer)
Considering this histogram, about how many students in the survey
paid more than $250 for textbooks?
a)
b)
c)
d)
29
47
52
71
Quantitative Variables
What three features can best describe the overall pattern of a histogram?
a)
b)
c)
d)
shape, center, skewness
center, spread, outliers
center, mean, symmetry
shape, center, spread
Quantitative Variables (answer)
What three features can best describe the overall pattern of a histogram?
a)
b)
c)
d)
shape, center, skewness
center, spread, outliers
center, mean, symmetry
shape, center, spread
Quantitative Variables
In the dataset represented by the following stemplot, how many
times does the number “28” occur? Leaf unit = 1.0.
0 9
1 246999
2 111134567888999
3 000112222345666699
a)
b)
c)
d)
0
1
3
4
4 001445
5 0014
6 7
7 3
Quantitative Variables (answer)
In the dataset represented by the following stemplot, how many
times does the number “28” occur? Leaf unit = 1.0.
0 9
1 246999
2 111134567888999
3 000112222345666699
a)
b)
c)
d)
0
1
3
4
4 001445
5 0014
6 7
7 3
Quantitative Variables
What is an advantage of histograms over stemplots?
a)
b)
c)
d)
They can be created by hand.
The dataset can be any size.
The actual data can be extracted from them.
They can be horizontal or vertical.
Quantitative Variables (answer)
What is an advantage of histograms over stemplots?
a)
b)
c)
d)
They can be created by hand.
The dataset can be any size.
The actual data can be extracted from them.
They can be horizontal or vertical.
Quantitative Variables
What is an advantage of stemplots over histograms?
a)
b)
c)
d)
They can use classes of any size.
The dataset can be any size.
The actual data can be extracted from them.
They can be horizontal or vertical.
Quantitative Variables (answer)
What is an advantage of stemplots over histograms?
a)
b)
c)
d)
They can use classes of any size.
The dataset can be any size.
The actual data can be extracted from them.
They can be horizontal or vertical.
Quantitative Variables
Residential Electricity Consumption
Plot A
a)
b)
c)
d)
Year
Plot A
Plot B
both
neither
Residential Electricity Consumption
Which of these plots is a time plot?
Plot B
Net Generation of Electricity
Quantitative Variables (answer)
Residential Electricity Consumption
Plot A
a)
b)
c)
d)
Year
Plot A
Plot B
both
neither
Residential Electricity Consumption
Which of these plots is a time plot?
Plot B
Net Generation of Electricity
Quantitative Variables
What type of trend does the following time plot show?
a)
b)
c)
downward
upward
no trend
Quantitative Variables (answer)
What type of trend does the following time plot show?
a)
b)
c)
downward
upward
no trend
Quantitative Variables
What would be the correct interpretation of the following graph?
a)
b)
c)
There is an upward trend in the data.
There is a downward trend in the data.
The data show seasonal variation.
Quantitative Variables (answer)
What would be the correct interpretation of the following graph?
a)
b)
c)
There is an upward trend in the data.
There is a downward trend in the data.
The data show seasonal variation.
Quantitative Variables
An individual value that falls outside the overall pattern is called ____________.
a)
b)
c)
d)
center
shape
outlier
spread
Quantitative Variables (answer)
An individual value that falls outside the overall pattern is called ____________.
a)
b)
c)
d)
center
shape
outlier
spread