Group Project2-27 March 2022
docx
keyboard_arrow_up
School
Johns Hopkins University *
*We aren’t endorsed by this school
Course
440.645
Subject
Industrial Engineering
Date
Jan 9, 2024
Type
docx
Pages
3
Uploaded by 77MIAO
Group Project 2 (Total Points 60)
Format
Please use this document to answer your questions.
The top left corner of the first page should contain the Group number and the full name
of each student.
Points will be deducted if the G
roup number and/or the full name of each student are
missing from the project.
Please type your answers in Word format and not as a PDF file.
Please use Excel wherever Excel solution is possible.
Please write clearly, the Excel commands that you applied to get your results.
Your Word document should appropriately include all the quantitative work performed
in Excel.
No handwritten project will be accepted.
Please do not email me any separate Excel file.
You will interchange the compiler within the group.
The compiler should be careful in compilation, to avoid typos and other errors that could
reduce project score.
The Word file should reach me as a single document and not as a bunch of jpeg or
similar pages.
No individual project will be accepted.
Dispatch
The compiler of each group will please email me one Word document only, by the
scheduled due date.
Group Assignments (excerpt from your Syllabus)
You will be assigned 2 group assignments.
Each group of 2 students will submit the results by the due date.
Each group will choose its compiler for every assignment, compiler varying from group to
group.
The compiler must provide a short memo stating the percentage of contribution by each
member, without mentioning the names.
Answers will be provided after due date.
You are expected to have an active presence and participation in group assignments to
maximize your learning.
Participation in group activities should be collaborative, equitable, of high quality, and reflect a
high level of academic thinking.
You will have an opportunity to privately rate your own participation and that of your
groupmate.
Group Project 2
60 Points
Show all steps
1.
(3+4+3=10 points) A production filling operation has a historical standard deviation of 6
ounces. When in proper adjustment, the mean filling weight for the production process
is 50 ounces. A quality control inspector periodically selects at random 36 containers and
uses the sample mean filling weight to see if the process is in proper adjustment.
a.
State the null and alternative hypotheses (3 points).
b.
Using a standardized test statistic and the critical value approach, test the hypothesis
at the 5% level of significance if the sample mean filling weight is 48.6 ounces (4
points).
c.
Develop a 95% confidence interval and use it to test the hypothesis (3 points).
2.
(10 points) A random sample of 200 physicians shows that there are 36 of them who
make at least $400,000 a year.
Can we conclude at the 1% significance level that the
true proportion of physicians in the population who make at least $400,000 a year is less
than 0.24? Use the p value method and explain how to use it to test the hypotheses.
3.
(10 points) Employees in a large company are entitled to 15-minute water breaks. A
random sample of the duration of water breaks for 10 employees was taken with the
times shown as: 12, 16, 14, 18, 21, 17, 19, 15, 18, and 16. Assuming that the times are
normally distributed, is there enough evidence at the 5% significance level to indicate
that on average employees are taking longer water breaks than they are entitled to?
4.
(5 points) During a natural gas shortage, a gas company randomly sampled residential
gas meters in order to monitor daily gas consumption. On a particular day, a sample of
100 meters showed a sample mean of 250 cubic feet and a sample standard deviation of
50 cubic feet. Provide a 90% confidence interval estimate of the mean gas consumption
for the population.
5.
(5 points) A CPA knows from past history that the average accounts receivable for a
company is $521.72 with a standard deviation of $584.64. If the auditor takes a simple
random sample of 100 accounts, what is the probability that the mean of the sample is
within $120 of the population mean?
6.
(2+4+4=10) A DVD rental store wants to know what proportion of its customers are
under age 21. A simple random sample of 500 customers was taken, and 375 of them
were under age 21. Presume that the true population proportion of customers under
age 21 is 0.68.
a.
Describe the shape of the sampling distribution of proportion of customers who are
under age 21 (2 points).
b.
Find the mean and standard deviation of
(1+3=4)
c.
What is the probability that the sample proportion
is within 0.03 of the true
proportion of customers who are under age 21? (4 points)
7.
(5 points) An economist is interested in studying the spending habits of consumers in a
particular region. The population standard deviation is known to be $1,000. A random
sample of 50 individuals resulted in an average expense of $15,000. What is the width of
the 99% confidence interval?
8.
(5 points)
An engineer for an electric fencing company is interested in the mean length of wires
being cut automatically by machine. The desired length of the wires is 12 feet. It is known that
the standard deviation in the cutting length is 0.15 feet. Suppose the engineer decided to
estimate the mean length to within 0.025 with 99% confidence. What sample size would be
needed?
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help