MATH 1280 Introduction to Statistics
UPDATED ACTUAL Questions and
CORRECT Answers
The population in this survey is: - CORRECT ANSWER - The target of the survey is to
assess the service that costumers get at the dealerships.
The correct answer is: Customers that arrive at dealerships of the company.
The sample in this survey is: - CORRECT ANSWER - that arrive at the selected
dealerships during the day of visit.
A parameter that may be targeted by this survey is: - CORRECT ANSWER - The
percentage of costumers that possess a car made by the company.
A statistic that may be used to summarize the outcome of the survey is: - CORRECT
ANSWER - The percentage, among costumers that were interviewed, of those that do not
possess a car made by the company
The data used to produce the tables and plots is: - CORRECT ANSWER - A sample.
The average number of calls that arrived between 8:00 AM and 8:10 AM during the working
days of any month is: - CORRECT ANSWER - A parameter.
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: - CORRECT ANSWER - A statistic.
In which of the months the number of incoming calls between 8:00 AM and 8:10 AM tends to be
smaller? - CORRECT ANSWER - February.
,The height of the fourth bar from the left of the bar plot for the month of February represents the
fact that? - CORRECT ANSWER - In 4 of the days of the month of February there were 5
incoming calls.
The location of the highest bar of the bar plot for the month of September represents the fact
that? - CORRECT ANSWER - 10 incoming calls came during 6 days of the month of
September.
The next two questions refer to the following relative frequency table on hurricanes that have
made direct hits on the U.S. between 1851 and 2004. Hurricanes are given a strength category
rating based on the minimum wind speed generated by the storm.
(http://www.nhc.noaa.gov/gifs/table5.gif ) (ALTERNATE DOWNLOAD LINK) - CORRECT
ANSWER -
What is the relative frequency of direct hits that were category 2 hurricanes? - CORRECT
ANSWER - 0.2637
The relative frequency of direct hits that were AT LEAST a category 3 storm is - CORRECT
ANSWER - 0.337
Sixty adults with gum disease were asked the number of times per week they used to floss before
their diagnoses. The (incomplete) results are shown below:
Flossing Frequency for Adults with Gum Disease# per WeekFreq.Relative Freq.Cum. Relative
Freq.0270.4500 118 3 0.933363 710.0167
Fill in the blanks in the table and answer the next two question: (The numerical answer that you
provide should be of the form "0.xxxx", with 4 digits to the right of the zero.) - CORRECT
ANSWER -
The relative frequency that flossed 6 times per week is: - CORRECT ANSWER - 0.05
The relative frequency that flossed at least once a week is: - CORRECT ANSWER - 0.55
, The number of malfunctioning products per production series was recorded for several
production series. The data was entered into an R object by the name "malfunction". The next 3
questions refer to the following R code: - CORRECT ANSWER -
The sample size is: - CORRECT ANSWER - 72
The frequency of production series where there are 4 malfunctioning products is: - CORRECT
ANSWER - 16
The frequency of production series where there are less than 7 malfunctioning products is: -
CORRECT ANSWER - 70
The file "ex2.csv" contains information on the blood pressure of a group of healthy individuals.
The file is located in http://pluto.huji.ac.il/~msby/StatThink/Datasets/ex2.csv. (ALTERNATE
DOWNLOAD LINK) Read the data into R and answer the following 4 questions - CORRECT
ANSWER -
The number of variables is: - CORRECT ANSWER -7
The type of the variable "id" is: - CORRECT ANSWER - factor
The type of the variable "sex" is: - CORRECT ANSWER - factor
The type of the variable "diastolic" is: - CORRECT ANSWER - numeric
A study was done to determine the age, type of activity, number of times per week and the
duration (amount of time) of resident use of a local park in San Jose. The first house in the
neighborhood around the park was selected randomly and then every 8th house in the
neighborhood around the park was interviewed. Answer the following 2 questions: - CORRECT
ANSWER -
UPDATED ACTUAL Questions and
CORRECT Answers
The population in this survey is: - CORRECT ANSWER - The target of the survey is to
assess the service that costumers get at the dealerships.
The correct answer is: Customers that arrive at dealerships of the company.
The sample in this survey is: - CORRECT ANSWER - that arrive at the selected
dealerships during the day of visit.
A parameter that may be targeted by this survey is: - CORRECT ANSWER - The
percentage of costumers that possess a car made by the company.
A statistic that may be used to summarize the outcome of the survey is: - CORRECT
ANSWER - The percentage, among costumers that were interviewed, of those that do not
possess a car made by the company
The data used to produce the tables and plots is: - CORRECT ANSWER - A sample.
The average number of calls that arrived between 8:00 AM and 8:10 AM during the working
days of any month is: - CORRECT ANSWER - A parameter.
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: - CORRECT ANSWER - A statistic.
In which of the months the number of incoming calls between 8:00 AM and 8:10 AM tends to be
smaller? - CORRECT ANSWER - February.
,The height of the fourth bar from the left of the bar plot for the month of February represents the
fact that? - CORRECT ANSWER - In 4 of the days of the month of February there were 5
incoming calls.
The location of the highest bar of the bar plot for the month of September represents the fact
that? - CORRECT ANSWER - 10 incoming calls came during 6 days of the month of
September.
The next two questions refer to the following relative frequency table on hurricanes that have
made direct hits on the U.S. between 1851 and 2004. Hurricanes are given a strength category
rating based on the minimum wind speed generated by the storm.
(http://www.nhc.noaa.gov/gifs/table5.gif ) (ALTERNATE DOWNLOAD LINK) - CORRECT
ANSWER -
What is the relative frequency of direct hits that were category 2 hurricanes? - CORRECT
ANSWER - 0.2637
The relative frequency of direct hits that were AT LEAST a category 3 storm is - CORRECT
ANSWER - 0.337
Sixty adults with gum disease were asked the number of times per week they used to floss before
their diagnoses. The (incomplete) results are shown below:
Flossing Frequency for Adults with Gum Disease# per WeekFreq.Relative Freq.Cum. Relative
Freq.0270.4500 118 3 0.933363 710.0167
Fill in the blanks in the table and answer the next two question: (The numerical answer that you
provide should be of the form "0.xxxx", with 4 digits to the right of the zero.) - CORRECT
ANSWER -
The relative frequency that flossed 6 times per week is: - CORRECT ANSWER - 0.05
The relative frequency that flossed at least once a week is: - CORRECT ANSWER - 0.55
, The number of malfunctioning products per production series was recorded for several
production series. The data was entered into an R object by the name "malfunction". The next 3
questions refer to the following R code: - CORRECT ANSWER -
The sample size is: - CORRECT ANSWER - 72
The frequency of production series where there are 4 malfunctioning products is: - CORRECT
ANSWER - 16
The frequency of production series where there are less than 7 malfunctioning products is: -
CORRECT ANSWER - 70
The file "ex2.csv" contains information on the blood pressure of a group of healthy individuals.
The file is located in http://pluto.huji.ac.il/~msby/StatThink/Datasets/ex2.csv. (ALTERNATE
DOWNLOAD LINK) Read the data into R and answer the following 4 questions - CORRECT
ANSWER -
The number of variables is: - CORRECT ANSWER -7
The type of the variable "id" is: - CORRECT ANSWER - factor
The type of the variable "sex" is: - CORRECT ANSWER - factor
The type of the variable "diastolic" is: - CORRECT ANSWER - numeric
A study was done to determine the age, type of activity, number of times per week and the
duration (amount of time) of resident use of a local park in San Jose. The first house in the
neighborhood around the park was selected randomly and then every 8th house in the
neighborhood around the park was interviewed. Answer the following 2 questions: - CORRECT
ANSWER -
