Suppose you are told that a 95% confidence interval for the average


2. Suppose you are told that a 95% confidence interval for the average price of a gallon of regular gasoline in your state is from $3.15 to $3.45. Use the fact that the confidence interval for the mean has the form x – E to  x  + E to compute the sample mean and the maximal margin of error E.

4.  Any state Auto Insurance Company took a random sample of 370 insurance claims paid out during a 1-year period.  The average claim paid was $1570. Assume ó = $250.  Find 0.90 and 0.99 confidence intervals for the mean claim payment.

5.  Three experiments investigating the relationship between need for cognitive closure and persuasion were reported in “Motivated Resistance and Openness to Persuasion in the Presence or Absence of Prior Information” by A.W. Kruglanski (Journal of Personality and Social Psychology, Vol. 65, No. 5 pp. 861-874).  Part of the study involved administering a “need for closure scale” to a group of students enrolled in an introductory psychology course.  The “need for closure scale” has scores ranging from 101 to 201.  For the 73 students in the highest quartile of the distribution, the mean score was x =178.70. Assume a population standard deviation of ó = 7.81.  These students were all classified as high on their need for closure.  Find a 95% confidence interval for the population mean score µ on the “need for closure scale” for all students with a high need for closure.

6.  How large a sample is needed in Problem 5 if we wish to be 99% confident that the sample mean score is within 2 points of the population mean score for students who are high on the need for closure?

7.  The Wind Mountain archaeological site is located in southwestern New Mexico.  Wind Mountain was home to a culture of prehistoric Native Americans called Anasazi.  A random sample of excavations at Wind Mountain gave the following depths (in centimeters) from present-day surface grade to the location of significant archaeological artifacts (Source: Mimbres Mogollon Archaeology, by A. Woosley and A. McIntyre, University of New Mexico Press):

85           45           120         80           75           55           65           60

65           95           90           70           75           65           68

a) Use a calculator with mean and sample standard deviation keys to verify thatx≈74.2 cm and s ≈18.3 cm.

b) Compute a 95% confidence interval for the mean depth µ at which archaeological artifacts from the Wind Mountain excavation site can be found.

8.  Shards of clay vessels were put together to reconstruct rim diameters of the original ceramic vessels found at the Wind Mountain archaeological site (see source in Problem 7).  A random sample of ceramic vessels gave the following rim diameters (in centimeters):

                15.9        13.4        22.1        12.7        13.1        19.6        11.7        13.5        17.7        18.1


a)      Use a calculator with mean and sample standard deviation keys to verify that x ≈ 15.8 cm and s ≈ 3.5 cm.

b)      Compute an 80% confidence interval for the population mean µ of rim diameters for such ceramic vessels found at the Wind Mountain archaeological site.

Study Locus
Calculate your paper price
Pages (550 words)
Approximate price: -

Why Work with Us

Top Quality and Well-Researched Papers

We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.

Professional and Experienced Academic Writers

We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.

Free Unlimited Revisions

If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account or by contacting our support.

Prompt Delivery and 100% Money-Back-Guarantee

All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. In case you cannot provide us with more time, a 100% refund is guaranteed.

Original & Confidential

We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text. We also promise maximum confidentiality in all of our services.

24/7 Customer Support

Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.

Try it now!

Calculate the price of your order

Total price:

How it works?

Follow these simple steps to get your paper done

Place your order

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Receive the final file

Once your paper is ready, we will email it to you.

Our Services

No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.


Essay Writing Service

No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.


Admission Essays & Business Writing Help

An admission essay is an essay or other written statement by a candidate, often a potential student enrolling in a college, university, or graduate school. You can be rest assurred that through our service we will write the best admission essay for you.


Editing Support

Our academic writers and editors make the necessary changes to your paper so that it is polished. We also format your document by correctly quoting the sources and creating reference lists in the formats APA, Harvard, MLA, Chicago / Turabian.


Revision Support

If you think your paper could be improved, you can request a review. In this case, your paper will be checked by the writer or assigned to an editor. You can use this option as many times as you see fit. This is free because we want you to be completely satisfied with the service offered.