1. Find the margin of error for the given values of c,s,and n. c=0.90,s=2.9,n=100

2. Construct the confidence interval for the population mean u. c=0.98, x=8.4,s=0.3,and n=55. A 985 confidence interval for u is: (_,_) Round to two decimal places as needed

3. C=0.90,x=15.8,s=7.0,and n=85

A 90% confidence interval for u is (_,_)

4.Find the minimum sample size needed to estimate u for the given values of c,s,and E.

c=0.90,s=8.8,and E=1. Assume that the preliminary sample has at least 30 members.

n=

5. A random sample of 50 home theatre systems has a mean price of $120.00 and a standard deviation is $19.90. Construct a 90% and a 95% confidence interval for the population mean. Then interpret the results.

6. A random sample of 43 gas grills has a mean price of $642.40 and a standard deviation of $59.70. The 90% confidence interval is:_____ and the 95% confidence interval is:_____ Which one is wider?

7. A random sample of 34 eight ounce servings of different juice drinks has a mean of 95.8 calories and a standard deviation of 44.3 calories. The 90% confidence interval is______ and the 95% confidence interval is ______. which one is wider?

8. People were polled on how many books they read the previous year. How many subjects are needed to estimate the number of books read the previous year within one book with 90% confidence. Initial survey results indicate that o=19.3 books. A 90% confidence level requires______ subjects? Round to the nearest whole number.

9. A doctor wants to estimate the cholesterol of all 20-29 year old females. How many subjects are needed to estimate the cholesterol within 3 points with 99% confidence assuming o=13.3? Suppose the doctor would be content with 90% confidence. How does the decrease in confidence affect the sample size required?

99% confidence level requires_____ subjects

90% confidence level requires _____ subjects

How does the decrease in confidence level affect the sample size?

10. Construct the confidence interval for the population mean u using (a) a t-distribution. (b) If you had incorrectly used a normal distribution, which interval would be wider?

a._______

b._____

11. (a) In a random sample of 10 adults the mean waste generated per person per day was 4.45 pounds and the standard deviation was 1.31 pounds. The 90% confidence interval is (__,__).

(b) What if the sample size was 400 adults. The 90% confidence level would be (__,__)

Was normal distribution or t-distribution used? And is (a) or (b) more narrow?

12. In a survey of 636 males ages 18-64, 390 say they have gone to the dentist in the past year. Construct 90% and 95% confidence intervals for the population portion. Interpret the results and compare the widths of confidence intervals.

13. In a survey of 6000 women, 3431 say they change their nail polish once a week. A 90% confidence interval for the population portion is (__,__) Round all intermediate values to the nearest thousandth.

14. A researcher wishes to estimate with 99% confidence, the proportion of adults who have high speed internet access. Her estimate must be accurate within 2% of the true portion.

What is the minimal sample size needed using a prior study that found that 54% of the respondents said they have high speed internet?

What is the minimal sample size needed assuming that no preliminary estimate is available?

15. Country A 62%.. Country B 90%… Country C 93%

2585 adults from country A, 1112 adults from country B, and 1081 adults from country C were asked if human activity contributes to global warming.

Construct a 95% confidence interval for the adults from country A.

Construct a 95% confidence interval for the adults from country B.

Construct a 95% confidence interval from the adults from country C.

16. 400 adults from the east, south, midwest, and west were asked if traffic congestion is a serious problem.

East 36%,South 32%,Midwest 25%, West 53%

95% CI for the portion of adults from the west (__,__)

95% CI for the portion of adults from the East (__,__)

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!

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.

Essays

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.

Admissions

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.

Reviews

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.

Reviews

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.