(Points : 10)

[117.61 120.09]

[117.36 119.39]

[116.18 119.82]

[115.67 120.33]

[115.82 120.18]

17. The changing ecology of the swamps in Louisiana has been the subject of much environmental research. One water-quality parameter of concern is the total phosphorous level. Suppose that the EPA makes 15 measurements in one area of the swamp, yielding a mean level of total phosphorus of 12.3 parts per billion (ppb) and a standard deviation of 5.4 ppb. The EPA wants to test whether the data support the conclusion that the mean level is less than 15 ppb. Calculate the appropriate test statistic to test the hypotheses. (Ch 9)

(Points : 10)

7.50

1.94

3.88

-1.94

-7.50

18. If we are testing the significance of the independent variable X1 and we reject the null hypothesis H0: b1=0, we conclude that:(Chs. 13 & 14)

(Points : 10)

X1 is significantly related to Y

X1 is not significantly related to Y

X1 is an unimportant independent variable

b1 is significantly related to the dependent variable Y

19. The Ohio Department of Agriculture tested 203 fuel samples across the state in 1999 for accuracy of the reported octane level. For premium grade, 14 out of 105 samples failed (they didn’t meet ASTM specification and the FTC Octane posting rule). How many samples would be needed to create a 99% confidence interval that is within 0.02 of the true proportion of premium grade fuel-quality failures?(Ch8)

(Points : 10)

4148

2838

1913

744

54

20. The area under the normal curve between z=2 and z=3 is ________________ the area under the normal curve between z=1 and z=2. (Ch 6) (Points : 10)

Greater than

Less than

Equal to

Answers 1, 2, or 3 depending on the value of the Mean

Answers 1, 2, or 3 depending on the value of the Standard Deviation

21. The least squares regression line minimizes the sum of the (Ch13)

(Points : 10)

Differences between actual and predicted Y values

Absolute deviations between actual and predicted Y values

Absolute deviations between actual and predicted X values

Squared differences between actual and predicted Y values

Squared differences between actual and predicted X values

22. In a manufacturing process a random sample of 36 bolts manufactured has a mean length of 3 inches with a standard deviation of .3 inches. What is the 99% confidence interval for the true mean length of the bolt? (Ch 8)

(Points : 10)

2.902 to 3.098

2.884 to 3.117

2.871 to 3.129

2.228 to 3.772

2.902 to 3.098

23. If a population distribution is known to be normal, then it follows that: (Ch7) (Points : 10)

The sample Mean must equal the population mean

The sample Mean is skewed for small samples but becomes more and more normal as sample size increases

The sample Standard Deviation must equal the population standard deviation

The Sample Proportion must equal the population Proportion

None of the above

24. If the sampled population has a mean 48 and standard deviation 16, then the mean and the standard deviation for the sampling distribution of X-bar (sample mean) for n=64 are: (Ch7)

(Points : 10)

4 and 4

12 and 4

48 and 2

48 and 1/4

48 and 16

25. A new company is in the process of evaluating its customer service. The company offers two types of sales: 1. Internet sales; 2. Store sales. The marketing research manager believes that the Internet sales are more than 10% higher than store sales. The null hypothesis would be: (Ch 10)

(Points : 10)

Pinternet–Pstore>.10

Pinternet–Pstore[removed]=.10

Pinternet–Pstore <=.10

Pinternet–Pstore=.10

26. A major airline company is concerned that its proportion of late arrivals has substantially increased in the past month. Historical data shows that on the average 18% of the company airplanes have arrived late. In a random sample of 1,240 airplanes, 310 airplanes have arrived late. If we are conducting a hypothesis test of a single proportion to determine if the proportion of late arrivals has increased: What is the value of the calculated test statistic? (Cch 9)

(Points : 10)

Z= 3.208

Z = 6.416

Z= -3.208

Z = -6.416

Z = 1.833

27. A confidence interval increases in width as: (Ch 8)

(Points : 10)

The level of confidence increases

Sample Size n decreases

Sample Standard Deviation increases

All of the above

28. In a manufacturing process, we are interested in measuring the average length of a certain type of bolt. Based on a preliminary sample of 100 bolts, the sample standard deviation is .3 inches. How many bolts should be sampled in order to make us 90% confident that the sample mean bolt length is within .02 inches of the true mean bolt length? (Ch8) (Points : 10)

865

609

1493

100

1000

29. For a given multiple regression model with three independent variables, the value of the adjusted multiple coefficient of determination is _________ less than R2.(Ch 14)

(Points : 10)

Always

Sometimes

Never

Can be greater or less depending on the standard error

30. A manufacturer of a chemical used in glue, attempting to control the amount of a hazardous chemical its workers are exposed to, has given instructions to halt production if the mean amount in the air exceeds 3.0ppm. A random sample of 50 air specimens produced the following statistics: sample mean=3.1 ppm , sample standard deviation=0.5 ppm. Calculate the appropriate test statistic to test the hypotheses. (Ch 9)

(Points : 10)

0.20

-0.20

10.00

1.41

-1.41

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.