In a study of academic procrastination, the authors of a paper reported that for a sample of 431 undergraduate students at a midsize public university preparing for a final exam in an introductory psychology course, the mean time spent studying for the exam was 7.24 hours and the standard deviation of study times was 3.50 hours. For purposes of this exercise, assume that it is reasonable to regard this sample as representative of students taking introductory psychology at this university.

(a) Construct a 95% confidence interval to estimate μ, the mean time spent studying for the final exam for students taking introductory psychology at this university. (Round your answers to three decimal places.)

(b) The paper also gave the following sample statistics for the percentage of study time that occurred in the 24 hours prior to the exam.

n = 431      x = 43.18      s = 21.26

Construct a 90% confidence interval for the mean percentage of study time that occurs in the 24 hours prior to the exam. (Round your answers to three decimal places.)
(  ,  ) ( , )

In a study of academic procrastination, the authors of a paper reported that for a sample of 481 undergraduate students at a midsize public university preparing for a final exam in an introductory psychology course, the mean time spent studying for the exam was 7.54 hours and the standard deviation of study times was 3.80 hours. For purposes of this exercise, assume that it is reasonable to regard this sample as representative of students taking introductory psychology at this university.

(a) Construct a 95% confidence interval to estimate μ, the mean time spent studying for the final exam for students taking introductory psychology at this university. (Round your answers to three decimal places.)

(b) The paper also gave the following sample statistics for the percentage of study time that occurred in the 24 hours prior to the exam.

n = 481      x = 43.78      s = 21.46

Construct a 90% confidence interval for the mean percentage of study time that occurs in the 24 hours prior to the exam. (Round your answers to three decimal places.)

In a study of academic procrastination, the authors of a paper reported that for a sample of 441 undergraduate students at a midsize public university preparing for a final exam in an introductory psychology course, the mean time spent studying for the exam was 7.74 hours and the standard deviation of study times was 3.40 hours. For purposes of this exercise, assume that it is reasonable to regard this sample as representative of students taking introductory psychology at this university.

a) Construct a 95% confidence interval to estimate μ, the mean time spent studying for the final exam for students taking introductory psychology at this university. (Round your answers to three decimal places.)

(__________ , __________ )

b) The paper also gave the following sample statistics for the percentage of study time that occurred in the 24 hours prior to the exam.

n = 441      x = 43.78      s = 21.46

Construct a 90% confidence interval for the mean percentage of study time that occurs in the 24 hours prior to the exam. (Round your answers to three decimal places.)

(_________ , _________ )

A confidence interval, at the 95% confidence level, will be used to answer the question, "What is the mean annual salary (in US dollars) of a Tesla car owner?"  Data was collected from 36 Tesla owners across the US. The mean annual salary of those 36 Tesla owners was $254000.  The standard deviation of ALL Tesla owners is known to be $1057.

a)  The value at the center of the confidence interval represents what quantity?  Choose an option from the list and type its corresponding letter in the box.  

1. sample size
2. population mean
3. sample mean
4. standard deviation

Answer for (a):

b)  Is z* or t* used when building this confidence interval?  Choose an option from the list and type its corresponding letter (A or B) in the box.

1. z*
2. t*

Answer for (b):

A confidence interval, at the 95% confidence level, will be used to answer the question, "What is the mean annual salary (in US dollars) of a Tesla car owner?"  Data was collected from 36 Tesla owners across the US. The mean annual salary of those 36 Tesla owners was $254000.  The standard deviation of ALL Tesla owners is known to be $1057.

a)  The value at the center of the confidence interval represents what quantity?  Choose an option from the list and type its corresponding letter in the box.  

1. sample size
2. population mean
3. sample mean
4. standard deviation

Answer for (a):  

b)  Is z* or t* used when building this confidence interval?  Choose an option from the list and type its corresponding letter (A or B) in the box.

1. z*
2. t*

Answer for (b):  

c) Determine the value of the letter indicated in part (b) using one of the following tables:  normal table, t table. Type the number, recorded to 3 decimals, in the box.

Answers for (c):

d) What are the lower and upper bounds of this confidence interval?   Type the numbers, rounded to 2 decimals, in their corresponding boxes.

Answers for (d): Lower Bound - ? Upper Bound - ?

e) If the sample size is decreased to 20 Tesla owners, what would happen to the confidence interval?   Choose an option and write its corresponding letter the blank below.

1. It narrows.
2. It widens.
3. It does not change.

Answer for (e): ?

Unemployment compensation has been a benefit available to most American workers for many decades. This benefit is provided though a combination of State and Federal programs. Funding for these programs comes from taxes paid by businesses on their payrolls. Discussion and debate has been on going regarding the level of benefits that should be paid, the length of time that these benefits should be paid, and the relative ecomomic benefit that the payments ultimately have.

Please comment on unemployment benefits, unemployment taxes and related matters by considering the following questions:

1. If you are aware of situations where the unemployment benefit system has benefited someone, or a situation where it has been abused by someone, please describe the situation. You don't need to use specific names, places or businesses, but give us a general discussion of what you knew to be true.

2. Give your opinion as to why the situtation was either beneficial or abusive. Suggest ways that the system could have worked inorder to catch the people who were taking advantage of the situation.

3. Discuss whether you believe that the taxes paid by businesses are excessive (consider the % required and the level of payroll that is taxed). Do these taxes help encourage or discourage businesses from locating in our state?

Case Study 6.3

Sniffing glue Could snuff profits

harvey benjaMin fuller founded The h. b. Fuller Company in 1887. Originally a one-man wallpaper-paste shop, H. B. Fuller is now a leading manufacturer of indus- trial glues, coatings, and paints, with operations worldwide. The company’s 10,000 varieties of glue hold together everything from cars to cigarettes to disposable diapers. However, some of its customers don’t use Fuller’s glues in the way they are intended to be used. That’s particularly the case in Central America, where Fuller derives 27 percent of its profits and where tens of thousands of homeless children sniff some sort of glue. Addicted to glue’s intoxicating but dangerous fumes, these unfortunate children are called resistoleros after Fuller’s Resistol brand. Child-welfare advocates have urged the company to add a noxious oil to its glue to discourage abusers, but the company has resisted, either because it might reduce the glue’s effectiveness or because it will irritate legitimate users.111 Either way, the issue is irritating H. B. Fuller, which has been recognized by various awards, honors, and socially conscious mutual funds as a company with a conscience. Fuller’s mission statement says that it “will conduct business legally and ethically, support the activities of its employees in their communities and be a responsible corporate citizen.” The St. Paul-based com- pany gives 5 percent of its profits to charity; it has committed itself to safe environmental practices worldwide (practices that are “often more stringent than local government standards,” the company says); and it has even endowed a chair in business ethics at the University of Minnesota. Now Fuller must contend with dissident stockholders inside, and demonstrators outside, its annual meetings. The glue-sniffing issue is not a new one. In 1969, the Testor Corporation added a noxious ingredient to its hobby glue to dis- courage abuse, and in 1994 Henkel, a German chemical com- pany that competes with Fuller, stopped making certain toxic glues in Central America. However, Fuller seems to have been singled out for criticism not only because its brand dominates Central America but also because—in the eyes of its critics, anyway—the company has not lived up to its own good-citizen image. Timothy Smith, executive director of the Interfaith Center for Corporate Responsibility, believes that companies with a reputation as good corporate citizens are more vulnerable to attack. “But as I see it,” he says, “the hazard is not in acting in a socially responsible way. The hazard is in over-marketing yourself as a saint.” Saintly or not, the company has made matters worse for itself by its handling of the issue. H. B. Fuller’s board of directors acknowledged that “illegal distribution was continuing” and that “a suitable replacement product would not be available in the near future.” Accordingly, it voted to stop selling Resistol adhe- sives in Central America. “We simply don’t believe it is the right decision to keep our solvent product on the market,” a company spokesman said. The Coalition on Resistoleros and other corporate gadflies were ecstatic, but their jubilation turned to anger when they learned a few months later that Fuller had not in fact stopped selling Resistol in Central America and did not intend to. True, Fuller no longer sold glue to retailers and small-scale users in Honduras and Guatemala, but it continued to sell large tubs and barrels of it to industrial customers in those countries and to a broader list of commercial and industrial users in neighboring countries. The company says that it has not only restricted distribution but also taken other steps to stop the abuse of its product. It has altered Resistol’s formula, replacing the sweet-smelling but highly toxic solvent toluene with the slightly less toxic chemi- cal cyclohexane. In addition, the company has tried—without success, it says—to develop a nonintoxicating water-based glue, and it contributes to community programs for homeless children in Central America. But the company’s critics disparage these actions as mere image polishing. Bruce Harris, director of Latin American programs for Covenant House, a nonprofit child- welfare advocate, asserts that Resistol is still readily available to children in Nicaragua and El Salvador and, to a lesser extent, in Costa Rica. “If they are genuinely concerned about the children,” he asks, “why haven’t they pulled out of all the countries—as their board mandated?”

After reading Case 6.3 on page 300 in the text, answer the following question: What are H. B. Fuller’s moral obligations in this case? What ideals, effects, and consequences are at stake? Have any moral rights been violated? What would a utilitarian recommend? A Kantian?

Would the following groups benefit if the US dollar appreciated? Yes or No. Explain.

1. Dutch pension funds holding US government bonds.

2. US manufacturing industries.

3. Australian tourists planning a trip to the US.

4. An American firm trying to purchase property overseas.

5. American tourists planning a trip to London.