Business 220 fall final exam

The following 11 questions are the take-home portion of the Final Exam.  You are allowed to use your books, notes, calculators, MS Excel, Minitab, and/or any other materials on ECN to answer the questions.  As in the business world, you may collaborate with your classmates (but NOT tutors or outside help) regarding the problems, but you must turn in your own completed work.  Your answers may be submitted either in written format or electronic (Word or PDF file format).  Possible partial credit may be given if you show your work, formulas, and/or assumptions.  Feel free to add more paper / space as needed.

IMPORTANT:  Your work can be submitted in either hard copy or electronic format (e.g. email attachment, ECN) in class on October 9th, 2013, or via electronic format by midnight on Saturday, October 12th, 2013.

 

 

1.  The waiting time for patients at a local hospital emergency department follows a normal distribution with a mean of 55 minutes and a population standard deviation of 15 minutes. The quality-assurance department found in a sample of 50 patients that the mean waiting time was 54 minutes. At the 0.025 significance level, decide if the sample data support the claim that the mean waiting time is less than 55 minutes.

State the null and alternative hypotheses.

State the decision rule.

Based on the sample data, state your decision in terms of the null hypothesis (reject or not reject). You may use either method, comparing the test statistic to the critical value, or the p-value approach.

 

 

2.  A machine makes ball bearings for use in other industrial machinery. The mean diameter of a particular type of ball bearing is 50 millimeters.  Based on a new vendor for their raw materials, the Quality Assurance manager is worried that the current production runs will be outside of specification. To test this, 100 ball bearings (n = 100) were sampled. The mean of the sample is 51.2 millimeters and the SAMPLE standard deviation is 1.223 millimeters.  Decide if the sample data supports the claim that the mean diameter is 50 millimeters.  Use a 0.02 level of significance.

State the null and alternative hypotheses.

State the decision rule.

Based on the sample data, state your decision in terms of the null hypothesis (reject or not reject). You may use either method, comparing the test statistic to the critical value, or the p-value approach.

 

3.  Based on the Nielsen ratings, the local CBS affiliate claims its 11:00 PM newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. If a = 0.01, what is our decision:

State the null and alternative hypotheses.

State the decision rule.

Based on the sample data, state your decision in terms of the null hypothesis (reject or not reject). 

 

4.  A study by a bank compared the average savings of customers who were depositors for three years or less, with those who had been depositors for more than three years. The results of a sample are:
 

 

< 3 Years

> 3 Years

Mean Savings Balance

$1,200

$1,250

Population Standard Deviation

$100

$250

Sample Size

100

150

 

Calculate the test statistic, z.

 

5.  Given the following hypothesis test:

 

H0p1 = p2

H1p1 p2

100 soil samples were taken from the bottom of Lake Erie, where 70 samples (X1) contained high levels of bacteria.  150 soil samples were taken from the bottom of Lake Superior, where 90 samples (X2) contained high levels of bacteria.

Using a significance level of 0.05, test the hypothesis:

State the decision rule.

What is the pooled proportion?

Compute the test statistic value.

What is the decision regarding the null hypothesis?

 

 

6.  An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. Seven customers were randomly selected and completed both surveys. The results follow: 

Customer

Pre-training survey

Post-training survey

A

6

8

B

5

5

C

10

10

D

7

10

E

6

8

F

5

6

G

2

8

 
What is the value of the test statistic, t?

 

7. Suppose that an automobile manufacturer designed a radically new lightweight engine and wants to recommend the grade of gasoline that will have the best fuel economy. The four grades are: below regular, regular, premium, and super premium. The test car made three trial runs on the test track using each of the four grades, and the miles per gallon were recorded:

 

Below Regular

Regular

Premium

Super Premium

36.69

39.31

38.99

40.04

40.00

39.87

40.02

39.89

41.01

39.87

39.99

39.93

 

a.       Create and show a single-factor ANOVA table with a 0.05 level of significance (a).

b.      Given that the null and alternative hypotheses are:

H0mbelow_regular = mregular = mpremium = msuper_premium

H1mbelow_regularmregularmpremiummsuper_premium

Based on the ANOVA table F statistics, what is the decision regarding the null hypothesis?

 

8. The college of business was interested in comparing the attendance for three different class times for a business statistics class.  The data follow:

  

 

a.       Create and show a two-factor ANOVA table with a 0.05 level of significance (a).

b.      What is the critical F statistic for testing the hypothesis of equal treatment means at the 0.05 level of significance (a)?

c.       Given that the null and alternative hypotheses are:

H0m8AM = m9:30AM = m11AM

H1m8AMm9:30AMm11AM

Based on the ANOVA table F statistics, what is the decision regarding the null hypothesis?

 

 

9.  Two research labs were asked to test the battery life in hours of 3 different experimental batteries.  Each lab performed 3 tests per battery type with the following results.

 

 

Battery Type 1

Battery Type 2

Battery Type 3

Lab 1

10.50

7.75

8.75

 

9.50

7.00

8.00

 

10.75

8.25

9.00

Lab 2

6.75

4.75

6.75

 

7.75

5.50

5.75

 

6.50

5.75

6.25

 

a.       Create and show a two-factor with interaction (replication) ANOVA table with a 0.05 level of significance (a).  Hint: There are 3 rows per sample.

b.      Based on the ANOVA table for Interaction, is there a statistically significant interaction between the labs and battery types (justify using either the F statistics or the p-value approach).

 

10.  Given the following table:

 

Current Length of Employment (Years)

Number of Workdays Absent

5

2

6

3

9

3

4

5

2

7

2

7

0

8

 

a.       Develop and state an estimate (predictor) equation for Ŷ given X.  You can calculate the a and b constants using any method, manual, Excel, Regression analysis, etc.

b.      Based on the estimate equation in part a, what is the estimated number of workdays absent given a worker who has been employed for 7 years?

c.       Determine the correlation coefficient.

d.      Perform a t-Test for the significance of the correlation coefficient for a two-tailed test with 0.05 level of significance (a).

e.       Determine the coefficient of determination.

f.       Determine the standard error of the estimate.

 

 

 

11.  Given the following table:

 

Labor Hours applied

Labor Cost

1000

$50755

945

$40622

850

$46111

1250

$77000

1300

$68190

1590

$75000

1425

$68444

1350

$71235

1650

$90673

1700

$101182

 

a.       Create a scatter plot of the data.

b.      Which is the independent variable?

c.       Which is the dependent variable?

d.      Does the data show a positive or negative correlation between X and Y?

 

 

Order a unique copy of this paper
(550 words)

Approximate price: $22

Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

We value our customers and so we ensure that what we do is 100% original..
With us you are guaranteed of quality work done by our qualified experts.Your information and everything that you do with us is kept completely confidential.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

The Product ordered is guaranteed to be original. Orders are checked by the most advanced anti-plagiarism software in the market to assure that the Product is 100% original. The Company has a zero tolerance policy for plagiarism.

Read more

Free-revision policy

The Free Revision policy is a courtesy service that the Company provides to help ensure Customer’s total satisfaction with the completed Order. To receive free revision the Company requires that the Customer provide the request within fourteen (14) days from the first completion date and within a period of thirty (30) days for dissertations.

Read more

Privacy policy

The Company is committed to protect the privacy of the Customer and it will never resell or share any of Customer’s personal information, including credit card data, with any third party. All the online transactions are processed through the secure and reliable online payment systems.

Read more

Fair-cooperation guarantee

By placing an order with us, you agree to the service we provide. We will endear to do all that it takes to deliver a comprehensive paper as per your requirements. We also count on your cooperation to ensure that we deliver on this mandate.

Read more

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
$26
The price is based on these factors:
Academic level
Number of pages
Urgency