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• My courses /
• MATH 1280 - AY2018-T3 /
• 1 February - 7 February /
• Self-Quiz Unit 1
Started on Thursday, 1 February 2018, 4:29 AM
State Finished
Completed on Thursday, 1 February 2018, 4:33 AM
Time taken 4 mins 16 secs
Grade 10.00 out of 10.00 (100%)
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An automobile producing company operates car dealerships that sell its cars. In order to assess the service
costumers get at the dealerships a team from the Customer Relationship Department was assembled. The
team was sent to 20 randomly selected dealerships. Each dealership was visited once by the team for an entire
working day. During a visit the team interviewed all the customers that arrived at that dealership.
One of the questions that each of the customers were asked is: "Do you currently possess a car made by our
company?" The answers were marked down as "Yes", "No", or "Refuse to Answer", depending on the
customer's response.
Select the correct answer in each of the following 4 questions:
Question 1
Correct
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Question text
The population in this survey is:
Select one:
a. The researchers that conducted the survey.
b. Customers that arrive at dealerships of the company.
c. The automobile producing company.
d. Owners of cars that are produced by the company.
Feedback
The target of the survey is to assess the service that costumers get at the dealerships.
Question 2
Correct
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, Question text
The sample in this survey is:
Select one:
a. The team that conducted the survey.
b. Customers that arrive at dealerships of the company.
c. "Yes", "No", or "Refuse to Answer".
d. Customers that arrive at the selected dealerships during the day of visit.
Feedback
All the costumers that arrive at dealerships are the population. The subset of those that arrive to the 20
dealerships that were selected are the sample.
Question 3
Correct
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A parameter that may be targeted by this survey is:
Select one:
a. The percentage of costumers that possess a car made by the company.
b. Customers that arrive at the selected dealerships during the day of visit.
c. "Yes", "No", or "Refuse to Answer".
d. Owners of cars that are produced by the company.
Feedback
"The percentage of costumers that possess a car made by the company" is the only answer that describes a
characteristic of the population. The last answer describes a subset of the population, not a characteristic: The
percentage of the subset within the entire population is a parameter, the subset itself is not.
Question 4
Correct
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A statistic that may be used to summarize the outcome of the survey is:
Select one:
,a. "Yes".
b. The percentage, among costumers that were interviewed, of those that do not possess a car made by the
company
c. Customers that arrive at the selected dealerships during the day of visit.
d. The team that conducted the survey.
Feedback
"The percentage, among costumers that were interviewed, of those that do not possess a car made by the
company" is the only answer that describes a characteristic of the sample. The third answer describes the
sample, not a characteristic of it: The percentage of the subset within the sample is a statistic, the sample itself
is not.
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The Customers Service Center of a large bank receive calls from customers. The number of incoming calls
between 8:00 AM and 8:10 AM in consecutive days were recorded. The number of incoming calls during the
working days of the month of September were:
8, 10, 6, 7, 12, 7, 8, 7, 8, 6, 9, 4, 6, 14, 10, 10, 10, 10, 6, 10, 12, 7
The number of incoming calls during the working days of the month of February were:
9, 11, 14, 6, 4, 6, 7, 3, 3, 2, 5, 6, 6, 5, 6, 7, 5, 4, 3, 5.
Create two R objects, one by the name "Sep", and the other by the name "Feb". The first object should contain
the first data and the second object should contain the second data. Produce a frequency table (with the
function "table") for each of the objects and a bar plot (with the combination of the function "plot" and the
function "table"). For comparison, bar plots like the one you should obtain are presented in Figure 1.6.
and Figure 1.7.
In light of the description given above, and based on the tables and/or the plots, select the correct answer in
each of the following 6 questions:
Question 5
Correct
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The data used to produce the tables and plots is:
Select one:
a. A population.
b. A sample.
c. A parameter.
d. A statistic.
, Feedback
The meaning of deciding that the given information is a population is that one's target in the investigation of
number of arriving calls is only with respect to the specific dates and times that are described in the question. It
is more likely that one has a broader interest, say the overall workload of the department. In such a case the
data represents number of incoming calls at other dates and times. Hence, it is a sample. A hint in favor of the
option that the data is a subset of a larger population of phone-tracking information is the sentence: "The
number of incoming calls between 8:00 AM and 8:10 AM in consecutive days were recorded."
Question 6
Correct
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The average number of calls that arrived between 8:00 AM and 8:10 AM during the working days of any month
is:
Select one:
a. A population.
b. A sample.
c. A parameter.
d. A statistic.
Feedback
The number of calls that arrived between 8:00 AM and 8:10 AM during the working days of any month in the
context of this question is a population. Consequently, the average is a characteristic of the population, namely
a parameter. A hint that the correct answer is a parameter and not a statistic is the fact that one cannot compute
the value of the average from the data. The computation requires data from other months, which we do not
have.
Question 7
Correct
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Question text
The average number of calls recorded in the object "Feb" is 5.85. The average in the object "Sep" is 8.5. The
difference between these two numbers is:
Select one:
a. A population.
b. A sample.
c. A statistic.
d. None of the above.
• My courses /
• MATH 1280 - AY2018-T3 /
• 1 February - 7 February /
• Self-Quiz Unit 1
Started on Thursday, 1 February 2018, 4:29 AM
State Finished
Completed on Thursday, 1 February 2018, 4:33 AM
Time taken 4 mins 16 secs
Grade 10.00 out of 10.00 (100%)
Information
Flag question
Information text
An automobile producing company operates car dealerships that sell its cars. In order to assess the service
costumers get at the dealerships a team from the Customer Relationship Department was assembled. The
team was sent to 20 randomly selected dealerships. Each dealership was visited once by the team for an entire
working day. During a visit the team interviewed all the customers that arrived at that dealership.
One of the questions that each of the customers were asked is: "Do you currently possess a car made by our
company?" The answers were marked down as "Yes", "No", or "Refuse to Answer", depending on the
customer's response.
Select the correct answer in each of the following 4 questions:
Question 1
Correct
Mark 1.00 out of 1.00
Flag question
Question text
The population in this survey is:
Select one:
a. The researchers that conducted the survey.
b. Customers that arrive at dealerships of the company.
c. The automobile producing company.
d. Owners of cars that are produced by the company.
Feedback
The target of the survey is to assess the service that costumers get at the dealerships.
Question 2
Correct
Mark 1.00 out of 1.00
Flag question
, Question text
The sample in this survey is:
Select one:
a. The team that conducted the survey.
b. Customers that arrive at dealerships of the company.
c. "Yes", "No", or "Refuse to Answer".
d. Customers that arrive at the selected dealerships during the day of visit.
Feedback
All the costumers that arrive at dealerships are the population. The subset of those that arrive to the 20
dealerships that were selected are the sample.
Question 3
Correct
Mark 1.00 out of 1.00
Flag question
Question text
A parameter that may be targeted by this survey is:
Select one:
a. The percentage of costumers that possess a car made by the company.
b. Customers that arrive at the selected dealerships during the day of visit.
c. "Yes", "No", or "Refuse to Answer".
d. Owners of cars that are produced by the company.
Feedback
"The percentage of costumers that possess a car made by the company" is the only answer that describes a
characteristic of the population. The last answer describes a subset of the population, not a characteristic: The
percentage of the subset within the entire population is a parameter, the subset itself is not.
Question 4
Correct
Mark 1.00 out of 1.00
Flag question
Question text
A statistic that may be used to summarize the outcome of the survey is:
Select one:
,a. "Yes".
b. The percentage, among costumers that were interviewed, of those that do not possess a car made by the
company
c. Customers that arrive at the selected dealerships during the day of visit.
d. The team that conducted the survey.
Feedback
"The percentage, among costumers that were interviewed, of those that do not possess a car made by the
company" is the only answer that describes a characteristic of the sample. The third answer describes the
sample, not a characteristic of it: The percentage of the subset within the sample is a statistic, the sample itself
is not.
Information
Flag question
Information text
The Customers Service Center of a large bank receive calls from customers. The number of incoming calls
between 8:00 AM and 8:10 AM in consecutive days were recorded. The number of incoming calls during the
working days of the month of September were:
8, 10, 6, 7, 12, 7, 8, 7, 8, 6, 9, 4, 6, 14, 10, 10, 10, 10, 6, 10, 12, 7
The number of incoming calls during the working days of the month of February were:
9, 11, 14, 6, 4, 6, 7, 3, 3, 2, 5, 6, 6, 5, 6, 7, 5, 4, 3, 5.
Create two R objects, one by the name "Sep", and the other by the name "Feb". The first object should contain
the first data and the second object should contain the second data. Produce a frequency table (with the
function "table") for each of the objects and a bar plot (with the combination of the function "plot" and the
function "table"). For comparison, bar plots like the one you should obtain are presented in Figure 1.6.
and Figure 1.7.
In light of the description given above, and based on the tables and/or the plots, select the correct answer in
each of the following 6 questions:
Question 5
Correct
Mark 1.00 out of 1.00
Flag question
Question text
The data used to produce the tables and plots is:
Select one:
a. A population.
b. A sample.
c. A parameter.
d. A statistic.
, Feedback
The meaning of deciding that the given information is a population is that one's target in the investigation of
number of arriving calls is only with respect to the specific dates and times that are described in the question. It
is more likely that one has a broader interest, say the overall workload of the department. In such a case the
data represents number of incoming calls at other dates and times. Hence, it is a sample. A hint in favor of the
option that the data is a subset of a larger population of phone-tracking information is the sentence: "The
number of incoming calls between 8:00 AM and 8:10 AM in consecutive days were recorded."
Question 6
Correct
Mark 1.00 out of 1.00
Flag question
Question text
The average number of calls that arrived between 8:00 AM and 8:10 AM during the working days of any month
is:
Select one:
a. A population.
b. A sample.
c. A parameter.
d. A statistic.
Feedback
The number of calls that arrived between 8:00 AM and 8:10 AM during the working days of any month in the
context of this question is a population. Consequently, the average is a characteristic of the population, namely
a parameter. A hint that the correct answer is a parameter and not a statistic is the fact that one cannot compute
the value of the average from the data. The computation requires data from other months, which we do not
have.
Question 7
Correct
Mark 1.00 out of 1.00
Flag question
Question text
The average number of calls recorded in the object "Feb" is 5.85. The average in the object "Sep" is 8.5. The
difference between these two numbers is:
Select one:
a. A population.
b. A sample.
c. A statistic.
d. None of the above.
