1. Two conditions for valid chance-based sampling methods are a) the interviewer does not choose the subject to be interviewed and b) the selection is based on probability. Give an example of each and comment on the compliance with these two conditions for the following sampling procedures:
   1. Simple random sampling:
   2. Voluntary response:
      State the population of interest, the sampling method, whether the sampling method is valid and the reasons for your answer for the following.
2. You want to investigate what factors lead to success in the fast-food business. You randomly select 25 establishments form the yellow pages of the local phone book for inclusion in the sample.
3. A late-night news program on the radio asks for viewers to register their opinions on a controversial subject by calling a 900 number.
4. Describe the type of bias you might encounter in question #3. What might you expect to see in the results of the survey? Your description should be in the context of the survey.
5. Which of the following is a reasonable conclusion about a distribution of the distances that employees drive to work when the mean is 13.1 miles and the standard deviation is 4.5 miles? Assume the distribution is bell shaped.
   1. Approximately 95% of the employee drives are with 9 miles of the mean value
   2. The minimum and first quartile are the same
   3. The distribution is skewed right
   4. The standard deviation is too large
   5. The distribution possesses outliers
6. Which of the following would not be a correct interpretation of a correlation coefficient of ?
   1. The variables are inversely related
   2. The coefficient of determination is .09
   3. 30% of the variation between the variables is linear
   4. There exists a weak linear association between the variables
   5. All are correct

7. What is the regression equation for this simple linear regression?

8. If you were interested in performing a multiple linear regression using job performance as the dependent variable and the following variables as possible independent variables: level of education, age, commuting distance, experience and training, what would be your first step in performing this analysis. Explain your choice.

9. If the time spent with a firm until one is promoted has a normal distribution with a mean of 28 months and a standard deviation of 5.3 months. What is the probability that an individual who has been with the company less than 21 months will be promoted?

1. 15%
2. 9%
3. .09%
4. 91%
5. 25%

10. If the 95% confidence interval for mean compensation (measured in thousands of dollars) for mid-level managers is , What was the sample mean used to determine this interval?

11. For question 10, provide an interpretation of this confidence interval.

12. The Department of Health plans to test the lead level in a specific park. Since a high lead level is harmful to children, the park will be closed if the lead level exceeds the allowed limit. The department randomly selects several locations in the park, gets soil samples form those locations, and tests the samples for their lead levels. Which of the following decisions would result in a type I error?

1. Closing the park when the lead levels are within the allowed limit
2. Keeping the park open when the lead levels are in excess of the allowed limit
3. Closing the park when the lead levels are in excess of the allowed limit
4. Keeping the park open when the lead levels are within the allowed limit
5. Closing the park because doing this hypothesis test is too hard

13. A department store in a large shopping mall claims that over 60% of the mall’s visitors shop at that store. Let be the proportion of the mall’s visitors that shop at the store. Which of the following pairs of hypotheses should be used to support this claim?

14. While performing a hypothesis test at the .05 significance level, you determine the p-value for your sample statistic is .001. What type of conclusion would you make and why?

15. What is the z-value that corresponds to area under a standardized normal distribution curve of 0.0764?

1. 
2. 
3. 
4. 
5. Cannot be determined

Section II : Case Problems

1. A simple random sample of 60 adults in a large urban area were asked to indicate the number of parking tickets that each had received over the last 5 years. The data is provided below.

1. Sketch a histogram of these data and describe the features of your graph..
2. What measure of center and spread is best associated with this data? Why?
3. Sketch the cumulative relative frequency graph of this data. What is the number of parking tickets received that corresponds to the 75 ^th percentile?

1. Use the height/weight data below for the following questions.

1. Construct a scatterplot and describe your plot.
2. What is the correlation coefficient? Interpret this value.
3. What is the regression equation for model?
4. Construct your residual plot.
5. Is your model appropriate? Explain why.
6. How good is your model as a prediction tool? Justify statistically.
7. If someone’s height is 66 inches, what would their predicted weight be? If that person’s weight was actually 118 lbs, calculate the residual value.

(3) A training agency is currently reviewing part of its operations. It runs a particular program

whereby young adults who are unemployed complete a training course that provides them with a variety of IT skills. On completion of the course, participants take a standardized test and receive an ability score. The agency then places trainees with local companies. The agency is trying to assess the wages its trainees receive from the companies they go to work for in relation to their ability scores and the number of years of relevant job experience the trainees had. The following data applies.

Analyze these data to determine whether Wage can be reliably predicted based on Score and Years of Experience. Show all of your work justifying your response.

4. The report ‘2005 Electronic Monitoring & Surveillance Survey: Many Companies Monitoring, Recording, Videotaping and Firing Employees’ summarized the results of a survey of 526 US businesses. The report stated that 137 of the 526 businesses fired workers for misuse of the Internet and 131 had fired workers for email misuse. For the purposes of this question, assume it is reasonable to regard this sample as representative of businesses in the US.

1. Construct and interpret a 95% confidence interval for the proportion of US businesses that have fired workers for misuse of the Internet.
2. If your sample proportion were .25 and your sample size was 15, what effect would this have on your construction of the confidence interval?
3. How large would your sample have to be in order for your interval to be within 2% of the true population proportion? Show your work.

5. Write a meaningful paragraph that includes the following six terms: hypotheses, p-value, reject H _o , and statistical significance. A meaningful paragraph is a coherent piece of writing that uses all of the listed words. The paragraph should show that you understand the meaning of the terms and their relationship to one another. A sequence of sentences that just define the terms is not a meaningful paragraph. Choosing a good context will make writing a meaningful paragraph easier.

6. A large multinational oil company is considering its strategy off the coast of Venezuela. The Venezuelan government has announced that a new drilling site will be offered for sale following a competitive bid process, the site going to the company making the highest bid. Provisional exploration of the site indicates that it can be expected to generate revenue of around $1500M if the oil reserves turn out to be high, about only $500M if they turn out to be low. Seismic tests have indicated that the probability of high reserves is 60%.

If the company is successful in its bid it will also have to decide whether to construct a new oil rig for the site or to move an existing oil rig which is currently operating at an uneconomic site. The cost of the new rig are approximately $250M and moving the existing rig is about $100M. A new rig would be able to boost oil production by $150M if reserve levels turned out to be high. The company has decided that if it is to bid for the site, the maximum bid it can afford is $750M. In the past, 70% of the company’s bids for such sites have been successful.

However, the company is under pressure to refurbish some of its existing rigs for both efficiency and safety reasons. The $750M could be used for this purpose instead. If the money is used for refurbishment, there is a 50% chance of increasing efficiency to generate a return on the $750M of 5% and a 50% chance of generating return of 10%. If the decision to refurbish takes place after the bid has been made and failed, only $500M will be available.

Construct a decision tree for this problem and suggest a suitable decision for management.

Price: $48.44

Solution: The downloadable solution consists of 22 pages, 2644 words and 40 charts.
Deliverable: Word Document