MATH 225N WEEK 6 DISCUSSION
CONFIDENCE INTERVAL PRACTICE TEST 2026
QUESTIONS WITH CORRECT SOLUTIONS
GRADED A+
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
Calculate the value of xmax.. Answer: 176
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
Calculate the value of xmin.. Answer: 52
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
What is the value of k using Sturges' Rule? It is sufficient to round
your answer to 2 decimal places.. Answer: 5.78
,◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
If k=5, what is the bin width given the formula in your notes? It is
sufficient to round your answer to 2 decimal places.. Answer: 24.8
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
The bin width calculated in the previous question will not be an
integer. Using the exact value that you get, construct the frequency
distribution tables using options A and B.
[Hint: The tables should consist of 2 columns - "Bin Limits" and
"Frequency." Under option A you should end up with 6 bins with the
first bin looking like "52 ≤ x < 76.8." Under option B you should end
up with 6 bins with the last bin looking like "151.2 < x ≤ 176."]
What is the frequency value corresponding to the third bin under
option A?. Answer: 10
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
, The bin width calculated will not be an integer. Using the exact value
that you get, construct the frequency distribution tables using
options A and B.
[Hint: The tables should consist of 2 columns - "Bin Limits" and
"Frequency." Under option A you should end up with 6 bins with the
first bin looking like "52 ≤ x < 76.8." Under option B you should end
up with 6 bins with the last bin looking like "151.2 < x ≤ 176."]
What is the frequency value corresponding to the fourth bin under
option B?. Answer: 10
◉ Which display is most likely to reveal association between X and
Y?. Answer: Scatter Plot
◉ A smooth distribution with one mode is negatively skewed
(skewed to the left). The median of the distribution is $65. Which of
the following is a reasonable value for the distribution mean?.
Answer: $54 (the mean would always be less than the median)
◉ As a measure of variability, compared to the range, an advantage
of the standard deviation is:. Answer: considering all data values
◉ So far this year, stock A has had a mean price of $6.58 per share
with a standard deviation of $1.88, while stock B has had a mean
price of $10.57 per share with a standard deviation of $3.02. Which
stock exhibits more relative variation?. Answer: Both exhibit the
same
CONFIDENCE INTERVAL PRACTICE TEST 2026
QUESTIONS WITH CORRECT SOLUTIONS
GRADED A+
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
Calculate the value of xmax.. Answer: 176
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
Calculate the value of xmin.. Answer: 52
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
What is the value of k using Sturges' Rule? It is sufficient to round
your answer to 2 decimal places.. Answer: 5.78
,◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
If k=5, what is the bin width given the formula in your notes? It is
sufficient to round your answer to 2 decimal places.. Answer: 24.8
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
The bin width calculated in the previous question will not be an
integer. Using the exact value that you get, construct the frequency
distribution tables using options A and B.
[Hint: The tables should consist of 2 columns - "Bin Limits" and
"Frequency." Under option A you should end up with 6 bins with the
first bin looking like "52 ≤ x < 76.8." Under option B you should end
up with 6 bins with the last bin looking like "151.2 < x ≤ 176."]
What is the frequency value corresponding to the third bin under
option A?. Answer: 10
◉ Consider the Excel data set "Data Dinner" posted on your course
home page. It consists of 28 observations on the amount spent on
dinner for four in downtown Chicago on Friday night. Now, using the
notations discussed in class, answer the following question.
, The bin width calculated will not be an integer. Using the exact value
that you get, construct the frequency distribution tables using
options A and B.
[Hint: The tables should consist of 2 columns - "Bin Limits" and
"Frequency." Under option A you should end up with 6 bins with the
first bin looking like "52 ≤ x < 76.8." Under option B you should end
up with 6 bins with the last bin looking like "151.2 < x ≤ 176."]
What is the frequency value corresponding to the fourth bin under
option B?. Answer: 10
◉ Which display is most likely to reveal association between X and
Y?. Answer: Scatter Plot
◉ A smooth distribution with one mode is negatively skewed
(skewed to the left). The median of the distribution is $65. Which of
the following is a reasonable value for the distribution mean?.
Answer: $54 (the mean would always be less than the median)
◉ As a measure of variability, compared to the range, an advantage
of the standard deviation is:. Answer: considering all data values
◉ So far this year, stock A has had a mean price of $6.58 per share
with a standard deviation of $1.88, while stock B has had a mean
price of $10.57 per share with a standard deviation of $3.02. Which
stock exhibits more relative variation?. Answer: Both exhibit the
same
