Question 1

Consider the following frequency distribution: $$\begin{array} { l c } 
\text { Class Interval } & \text { Frequency } \
10 \text {-under } 20 & 15 \
20 \text {-under } 30 & 25 \
30 \text {-under } 40 & 10
\end{array}$$
What is the relative frequency of the first class?
A)0.15
B)0.30
C)0.10
D)0.20
E)0.40

Accepted Answer

The relative frequency of the first class is calculated by dividing the frequency of the first class by the total frequency. The total frequency is $15 + 25 + 10 = 50$. The relative frequency of the first class is $15 / 50 = 0.30$.

Question 2

Time-series data should be shown from oldest time period to the most recent.

Accepted Answer

Time-series data is typically displayed from the oldest time period to the most recent to accurately reflect the sequence of events and trends over time.

Question 3

When looking at a scatter plot, if a trend can be discerned between changes in one variable that appear to be related to changes in the other variable, there is likely a relationship between the two variables.

Accepted Answer

The answer of When looking at a scatter plot, if...

Question 4

To compare two series of data during the same time period, the graph should show the first and then show the second after that, all in one line.

Accepted Answer

To compare two series of data during the same time period, a graph should ideally display both series simultaneously, using different colors, symbols, or line styles for clarity, not sequentially in one line.

Question 5

The cumulative frequency for a class is 27.The cumulative frequency for the next (non-empty)class will be _______.
A)less than 27
B)equal to 27
C)next class frequency minus 27
D)27 minus the next class frequency
E)27 plus the next class frequency

Accepted Answer

The cumulative frequency for a class is the sum of the frequencies for all classes up to and including that class. Therefore, the cumulative frequency for the next class will be the cumulative frequency of the current class (27) plus the frequency of the next class.

Question 6

The number of phone calls arriving at a switchboard each hour has been recorded, and the following frequency distribution has been developed. 
$$\begin{array} { l c } 
\text { Class Interval } & \text { Frequency } \
20 \text {-under } 40 & 30 \
40 \text {-under } 60 & 45 \
60 \text {-under } 80 & 80 \
80 \text {-under } 100 & 45
\end{array}$$
What is the cumulative frequency of the third class?
A)80
B)0.40
C)155
D)75
E)105

Accepted Answer

The answer of The number of phone calls arriving at...

Question 7

Consider the following frequency distribution: $$\begin{array} { l c } 
\text { Class Interval } & \text { Frequency } \
10 \text {-under } 20 & 15 \
20 \text {-under } 30 & 25 \
30 \text {-under } 40 & 10
\end{array}$$
What is the midpoint of the first class?
A)10
B)20
C)15
D)30
E)40

Accepted Answer

The midpoint of a class interval is calculated by adding the lower limit to the upper limit of the class and then dividing by 2. For the first class interval (10-under 20), the midpoint is (10 + 20) / 2 = 15.

Question 8

The number of phone calls arriving at a switchboard each hour has been recorded, and the following frequency distribution has been developed. 
$$\begin{array} { l c } 
\text { Class Interval } & \text { Frequency } \
20 \text {-under } 40 & 30 \
40 \text {-under } 60 & 45 \
60 \text {-under } 80 & 80 \
80 \text {-under } 100 & 45
\end{array}$$
What is the midpoint of the last class?
A)80
B)100
C)95
D)90
E)85

Accepted Answer

The midpoint of a class interval is calculated by averaging the lower and upper boundaries of the class. For the last class (80-under 100), the midpoint is (80 + 100) / 2 = 90.

Question 9

The following class intervals for a frequency distribution were developed to provide information regarding the starting salaries for students graduating from a particular school: $\begin{array}{c}
\begin{array}{lll}
\text {Salary}\
\
\
\
\
\
\end{array}
\begin{array}{lll}
\text {Number of Graduates}\
\text { (\$1,000s) } \
\text { 28-under } 31 \
\text { 31-under } 34 \
\text { 34-under } 35 \
\text { 35-under } 38 
\end{array}
\begin{array}{lll}
\
\
-\
-\
-\
-\

\end{array}

\end{array}$

Before data were collected, someone questioned the validity of this arrangement.Which of the following represents a problem with this set of intervals?
A)The intervals are too wide.
B)More classes are needed as the numbers are in the thousands.
C)The first interval should start at 0.
D)The second and the third interval overlap.
E)The third interval is smaller than the others.

Accepted Answer

The answer of The following class intervals for a frequency...

Question 10

To consider historical data as part of their decisions, management often uses time-series data.

Accepted Answer

Time-series data, which is a sequence of data points collected or recorded at successive points in time, is often used by management to analyze trends, patterns, and to forecast future conditions, making it a valuable tool for considering historical data in decision-making processes.

Question 11

A person has decided to construct a frequency distribution for a set of data containing 60 numbers.The lowest number is 23 and the highest number is 68.If 7 classes are used, the class width should be approximately _______.
A)5
B)7
C)9
D)11
E)12

Accepted Answer

The answer of A person has decided to construct a...

Question 12

The point of "cleaning" time-series data is to be sure all the data are accurate.

Accepted Answer

The point of cleaning time-series data is to identify and correct errors or inconsistencies, handle missing values, and ensure the data is in a suitable format for analysis, rather than to guarantee all data are accurate.

Question 13

The following class intervals for a frequency distribution were developed to provide information regarding the starting salaries for students graduating from a particular school: $$\begin{array} { l c } 
\begin{array} { l } 
\text { Salary } \
\text { (\$1,000s) }
\end{array} & \text { Number of Graduates } \
\text { 28-under 31 } & - \
\text { 31-under 35 } & - \
\text { 34-under 37 } & - \
\text { 39-under 40 } & -
\end{array}$$
Before data were collected, someone questioned the validity of this arrangement.Which of the following represents a problem with this set of intervals?
A)There are too many intervals.
B)The class widths are too small.
C)Some numbers between 28,000 and 40,000 would fall into two different intervals.
D)The first and the second interval overlap.
E)There are too few intervals.

Accepted Answer

Some numbers between 28,000 and 40,000 would fall into two different intervals.

Question 14

An instructor made a frequency table of the scores his students got on a test 
$$\begin{array} { c c } 
\text { Score } & \text { Frequency } \
30 \text {-under } 40 & 1 \
40 \text {-under } 50 & 4 \
50 \text {-under } 60 & 5 \
60 \text {-under } 70 & 10 \
70 \text {-under } 80 & 20 \
80 \text {-under } 90 & 10 \
90 \text {-under } 100 & 5
\end{array}$$
Approximately what percent of students got more than 70?
A)36
B)20
C)50
D)10
E)64

Accepted Answer

To find the percentage of students who scored more than 70, add the frequencies of scores from the ranges 70-under 80, 80-under 90, and 90-under 100: 20 + 10 + 5 = 35. The total number of students is the sum of all frequencies: 1 + 4 + 5 + 10 + 20 + 10 + 5 = 55. The percentage is (35/55) * 100 ≈ 63.64%, which rounds to approximately 64%.

Question 15

Consider the following frequency distribution: $$\begin{array} { l c } 
\text { Class Interval } & \text { Frequency } \
10 \text {-under } 20 & 15 \
20 \text {-under } 30 & 25 \
30 \text {-under } 40 & 10
\end{array}$$
What is the cumulative frequency of the second class interval?
A)25
B)40
C)15
D)50

Accepted Answer

The cumulative frequency of the second class interval is the sum of the frequencies of the first and second class intervals, which is 15 (from the first interval) + 25 (from the second interval) = 40.

Question 16

The number of phone calls arriving at a switchboard each hour has been recorded, and the following frequency distribution has been developed. 
$$\begin{array} { l c } 
\text { Class Interval } & \text { Frequency } \
20 \text {-under } 40 & 30 \
40 \text {-under } 60 & 45 \
60 \text {-under } 80 & 80 \
80 \text {-under } 100 & 45
\end{array}$$
What is the relative frequency of the second class?
A)0.455
B)0.900
C)0.225
D)0.750
E)0.725

Accepted Answer

The relative frequency is calculated by dividing the frequency of the class by the total frequency. The total frequency is 200 (30+45+80+45). The relative frequency for the second class is 45/200 = 0.225.

Question 17

An instructor made a frequency table of the scores his students got on a test 
$$\begin{array} { c c } 
\text { Score } & \text { Frequency } \
30 \text {-under } 40 & 1 \
40 \text {-under } 50 & 4 \
50 \text {-under } 60 & 5 \
60 \text {-under } 70 & 10 \
70 \text {-under } 80 & 20 \
80 \text {-under } 90 & 10 \
90 \text {-under } 100 & 5
\end{array}$$
The midpoint of the last class interval is _________.
A)90
B)5
C)95
D)100
E)50

Accepted Answer

The midpoint of a class interval is calculated by adding the lower limit to the upper limit of the class and then dividing by 2. For the last class interval (90 - under 100), the midpoint is (90 + 100) / 2 = 95.

Question 18

Visualization of time-series data is considered descriptive business analytics.

Accepted Answer

Visualization of time-series data is a form of descriptive business analytics because it involves summarizing and presenting historical data in a visual format to understand past behaviors or trends.

Question 19

A frequency distribution was developed.The lower endpoint of the first class is 9.30, and the midpoint is 9.35.What is the upper endpoint of this class?
A)9.50
B)9.60
C)9.70
D)9.40
E)9.80

Accepted Answer

The midpoint is the average of the lower and upper endpoints. If the lower endpoint is 9.30 and the midpoint is 9.35, the upper endpoint can be calculated as 9.40.

Question 20

To show differences between different series during the same time periods, different trend lines, each in a different color, and all using the same x axis for graphing.

Accepted Answer

Using different colored trend lines for each series on the same graph with a shared x-axis effectively highlights differences and trends over the same time periods, allowing for easy comparison.

Quiz 2: Visualizing Data With Charts and Graphs

Consider the following frequency distribution: $\begin{array} { l c } \text { Class Interval } & \text { Frequency } \\10 \text {-under } 20 & 15 \\20 \text {-under } 30 & 25 \\30 \text {-under } 40 & 10\end{array}$ What is the relative frequency of the first class?

Time-series data should be shown from oldest time period to the most recent.

When looking at a scatter plot, if a trend can be discerned between changes in one variable that appear to be related to changes in the other variable, there is likely a relationship between the two variables.

To compare two series of data during the same time period, the graph should show the first and then show the second after that, all in one line.

The cumulative frequency for a class is 27.The cumulative frequency for the next (non-empty) class will be _______.

Consider the following frequency distribution: $\begin{array} { l c } \text { Class Interval } & \text { Frequency } \\10 \text {-under } 20 & 15 \\20 \text {-under } 30 & 25 \\30 \text {-under } 40 & 10\end{array}$ What is the midpoint of the first class?

To consider historical data as part of their decisions, management often uses time-series data.

A person has decided to construct a frequency distribution for a set of data containing 60 numbers.The lowest number is 23 and the highest number is 68.If 7 classes are used, the class width should be approximately _______.

The point of "cleaning" time-series data is to be sure all the data are accurate.

Consider the following frequency distribution: $\begin{array} { l c } \text { Class Interval } & \text { Frequency } \\10 \text {-under } 20 & 15 \\20 \text {-under } 30 & 25 \\30 \text {-under } 40 & 10\end{array}$ What is the cumulative frequency of the second class interval?

Visualization of time-series data is considered descriptive business analytics.

A frequency distribution was developed.The lower endpoint of the first class is 9.30, and the midpoint is 9.35.What is the upper endpoint of this class?

To show differences between different series during the same time periods, different trend lines, each in a different color, and all using the same x axis for graphing.