While you are required to work together on this quiz, each member of the
group must submit his or her own answers in order to receive credit.
If needed, here's a link to the Normal Probability Applet (Links to an external
site.)Links to an external site..
You will need the following data sets.
RatesOfReturn.xlsx (Links to an external
site.)Links to an external site.
DirectFlightCosts.xlsx (Links to an
external site.)Links to an external site.
When calculating anything, please remember to round to three decimal
places, unless otherwise specified. DO NOT ROUND until your calculation
is complete.
Question 1
pts
I met with my group and completed this Group Quiz with them.
Correct!
True
Question 2
pts
Which of the following variables is/are quantitative? (Mark all that apply.)
The telephone number of a randomly selected business in town.
The 3 most common brands of car found in the US.
Correct!
The number of people in a randomly selected classroom on campus.
Question 3
pts
Students in an Introductory Statistics class at BYU-Idaho were studying prices
of cold cereal at grocery stores in Rexburg. To get a sample of cold cereal
prices, they went to Albertson's and rolled a die to decide which box from the
left of the top shelf they would start on. They then recorded every 6th cereal
after the first, moving from left to right down the shelves, recording the
,name, size, and price of each cereal in their sample. Is this study an
experiment or an observational study, and why?
An observational study, because the students had no control over which
cereals were selected.
Correct!
An observational study, because the students had no control over the price
of the individual cereals.
An experiment, because the students had control over which sampling
method they used.
An experiment, because the students had control over which cereals would
be selected for the study.
Question 4
pts
For a Math 221 project, one group of students studied the ages of students
on the BYU-Idaho campus. They collected data from a random sample
of n=100 students. The sample mean was 21.2 and the sample standard
deviation was 2.61. An excerpt of their data is given below.
The group notices an error in their data. The age of one of the males (ID=3)
was entered incorrectly. He is actually 21 years old. When the error is
corrected, what will happen to the sample median?
The median will increase.
The median will decrease.
Correct!
, It is not possible to determine this without the full data set.
The median will stay the same.
Question 5
pts
The time to complete a standardized exam in the BYU-Idaho Testing Center is
approximately normal with a mean of 70 minutes and a standard deviation of
10 minutes. Using the 68-95-99.7 rule, approximately what percentage of
students will complete the exam in under fifty minutes? Give your answer
accurate to one decimal place. (Example: 24.7)
Correct!
Correct Answers
2.5 (with margin: 0.0)
Question 6
pts
The scores on the LSAT are approximately normal with mean of 150.7 and
standard deviation of 10.2. (Source: www.lsat.org.) Queen's School of
Business in Kingston, Ontario requires a minimum LSAT score of 157 for
admission.
Find the 35th percentile of the LSAT scores. Give your answer accurate to
one decimal place. Use the applet. (Example: 124.7)
Correct!
Correct Answers
146.8 (with margin: 0.3)
Question 7
pts
A team of dermatological researchers were studying skin cancer among 60-
70 year old American men. Suppose you were a part of the research team
and take a sample of men from this age group and calculate the mean
number of skin cancer spots in the sample. Also suppose that it is known that
the distribution of the number of cancer spots is right-skewed.
Suppose the sample size for this study was n=2. What would be the shape
of the distribution of sample means?
Correct!
Skewed right.
group must submit his or her own answers in order to receive credit.
If needed, here's a link to the Normal Probability Applet (Links to an external
site.)Links to an external site..
You will need the following data sets.
RatesOfReturn.xlsx (Links to an external
site.)Links to an external site.
DirectFlightCosts.xlsx (Links to an
external site.)Links to an external site.
When calculating anything, please remember to round to three decimal
places, unless otherwise specified. DO NOT ROUND until your calculation
is complete.
Question 1
pts
I met with my group and completed this Group Quiz with them.
Correct!
True
Question 2
pts
Which of the following variables is/are quantitative? (Mark all that apply.)
The telephone number of a randomly selected business in town.
The 3 most common brands of car found in the US.
Correct!
The number of people in a randomly selected classroom on campus.
Question 3
pts
Students in an Introductory Statistics class at BYU-Idaho were studying prices
of cold cereal at grocery stores in Rexburg. To get a sample of cold cereal
prices, they went to Albertson's and rolled a die to decide which box from the
left of the top shelf they would start on. They then recorded every 6th cereal
after the first, moving from left to right down the shelves, recording the
,name, size, and price of each cereal in their sample. Is this study an
experiment or an observational study, and why?
An observational study, because the students had no control over which
cereals were selected.
Correct!
An observational study, because the students had no control over the price
of the individual cereals.
An experiment, because the students had control over which sampling
method they used.
An experiment, because the students had control over which cereals would
be selected for the study.
Question 4
pts
For a Math 221 project, one group of students studied the ages of students
on the BYU-Idaho campus. They collected data from a random sample
of n=100 students. The sample mean was 21.2 and the sample standard
deviation was 2.61. An excerpt of their data is given below.
The group notices an error in their data. The age of one of the males (ID=3)
was entered incorrectly. He is actually 21 years old. When the error is
corrected, what will happen to the sample median?
The median will increase.
The median will decrease.
Correct!
, It is not possible to determine this without the full data set.
The median will stay the same.
Question 5
pts
The time to complete a standardized exam in the BYU-Idaho Testing Center is
approximately normal with a mean of 70 minutes and a standard deviation of
10 minutes. Using the 68-95-99.7 rule, approximately what percentage of
students will complete the exam in under fifty minutes? Give your answer
accurate to one decimal place. (Example: 24.7)
Correct!
Correct Answers
2.5 (with margin: 0.0)
Question 6
pts
The scores on the LSAT are approximately normal with mean of 150.7 and
standard deviation of 10.2. (Source: www.lsat.org.) Queen's School of
Business in Kingston, Ontario requires a minimum LSAT score of 157 for
admission.
Find the 35th percentile of the LSAT scores. Give your answer accurate to
one decimal place. Use the applet. (Example: 124.7)
Correct!
Correct Answers
146.8 (with margin: 0.3)
Question 7
pts
A team of dermatological researchers were studying skin cancer among 60-
70 year old American men. Suppose you were a part of the research team
and take a sample of men from this age group and calculate the mean
number of skin cancer spots in the sample. Also suppose that it is known that
the distribution of the number of cancer spots is right-skewed.
Suppose the sample size for this study was n=2. What would be the shape
of the distribution of sample means?
Correct!
Skewed right.
