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Statistics for Business and Economics | 12th Edition | ISBN: 9780321826237 | Authors: James T. McClave, P. George Benson, Terry T Sincich

Statistics for Business and Economics 12th Edition solutions

Author: James T. McClave, P. George Benson, Terry T Sincich
Publisher: Pearson
ISBN: 9780321826237
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Chapter 8 Problems

Chapter: 8 Problem: 1E

Statistics for Business and Economics 12
Problem 1E The purpose of this exercise is to compare the variability of and with the variability of . a. Suppose the first sample is selected from a population with mean = 150 and variance = 900. Within what range should the sample mean vary about 95% of the time in repeated samples of 100 m

Chapter: 8 Problem: 2E

Statistics for Business and Economics 12
Problem 2E Independent random samples of 64 observations each are chosen from two normal populations with the following means and standard deviations: Let and denote the two sample means. a. Give the mean and standard deviation of the sampling distribution of b. Give the mean and standard de

Chapter: 8 Problem: 3E

Statistics for Business and Economics 12
Problem 3E In order to compare the means of two populations, independent random samples of 400 observations are selected from each population, with the following results: Sample 1 Sample 2 = 5,275 = 5,240 s1 = 150 s2 = 200 a. Use a 95% confidence interval to estimate the difference

Chapter: 8 Problem: 4E

Statistics for Business and Economics 12
To use the t-statistic to test for a difference between the means of two populations, what assumptions must be made about the two populations? About the two samples?

Chapter: 8 Problem: 5E

Statistics for Business and Economics 12
Two populations are described in each of the following cases. In which cases would it be appropriate to apply the small-sample t-test to investigate the difference between the population means? a. Population 1: Normal distribution with variance \(\sigma_{1}^{2}\). Population 2: Skewed to the righ

Chapter: 8 Problem: 6E

Statistics for Business and Economics 12
Problem 6E Assume that Calculate the pooled estimator of s2 for each of the following cases: Note that the pooled estimate is a weighted average of the sample variances. To which of the variances does the pooled estimate fall nearer in each of the above cases?

Chapter: 8 Problem: 7E

Statistics for Business and Economics 12
Independent random samples from normal populations produced the results shown in the next table. a. Calculate the pooled estimate of \(\sigma^2\). b. Do the data provide sufficient evidence to indicate that \(\mu_2>\mu_1\)? Test using \(\alpha=.10\). c. Find a 90% confidence interval for

Chapter: 8 Problem: 8E

Statistics for Business and Economics 12
Problem 8E Two independent random samples have been selected 100 observations from population 1 and 100 from population 2. Sample means = 26.6 and = 15.5 were obtained. From previous experience with these populations, it is known that the variances are = 9 and = 16. a. Find s b. Sketch the ap

Chapter: 8 Problem: 9E

Statistics for Business and Economics 12
Independent random samples of \(n_1=233\ \text{and}\ n_2=312\) are selected from two populations and used to test the hypothesis \(H_0:(\mu_1-\mu_2)=0\) against the alternative \(H_a:(\mu_1-\ \mu_2)\ \neq\ 0\). a. The two-tailed p-value of the test is .1150. Interpret this result. b. If the a

Chapter: 8 Problem: 10E

Statistics for Business and Economics 12
Problem 10E Independent random samples from approximately normal populations produced the results shown below. a. Do the data provide sufficient evidence to conclude that (2 - 1) > 10? Test using ? = .01. b. Construct a 98% confidence interval for (2 - 1). Interpret your result.

Chapter: 8 Problem: 11E

Statistics for Business and Economics 12
Problem 11E Independent random samples selected from two normal populations produced the sample means and standard deviations shown below. a. Conduct the test H0: (1 - 2) = 0 against Ha: (1 - 2) ? 0. Interpret the results. b. Estimate (1 - 2) using a 95% confidence interval.

Chapter: 8 Problem: 12E

Statistics for Business and Economics 12
Lobster trap placement. Refer to the Bulletin of Marine Science (April 2010) study of lobster trap placement, Exercise. Recall that the variable of interest was the average distance separating trapscalled trap spacingdeployed by teams of fishermen fishing for the red spiny lobster in Baja California

Chapter: 8 Problem: 13E

Statistics for Business and Economics 12
Problem 13E Last name and acquisition timing. The speed with which consumers decide to purchase a product was investigated in the Journal of Consumer Research (August 2011). The researchers theorized that consumers with last names that begin with letters later in the alphabet will tend to acquire i

Chapter: 8 Problem: 14E

Statistics for Business and Economics 12
Effectiveness of teaching software. Educational software ranging from video-game-like programs played on Sony PlayStations to rigorous drilling exercises used on computers has become very popular in school districts across the country. The U.S. Department of Education (DOE) recently conducted a natio

Chapter: 8 Problem: 15E

Statistics for Business and Economics 12
Problem 15E Childrens recall of TV ads. Marketing professors at Robert Morris and Kent State Universities examined childrens recall and recognition of television advertisements (Journal of Advertising, Spring 2006). Two groups of children were shown a 60-second commercial for Sunkist FunFruit Rock-

Chapter: 8 Problem: 16E

Statistics for Business and Economics 12
Drug content assessment. Refer to Exercise 4.123 (p. 240) and the Analytical Chemistry (Dec. 15, 2009) study in which scientists used high-performance liquid chromatography to determine the amount of drug in a tablet. Twenty-five tablets were produced at each of two different, independent sites. Drug

Chapter: 8 Problem: 17E

Statistics for Business and Economics 12
Problem 17E Buy-side vs. sell-side analysts earnings forecasts. Refer to the Financial Analysts Journal (Jul./Aug. 2008) study of financial analysts forecast earnings, Exercise 2.86 (p. 86). Recall that data were collected on 3,526 forecasts made by buy-side analysts and 58,562 forecasts made by se

Chapter: 8 Problem: 18E

Statistics for Business and Economics 12
Problem 18E Homework assistance for accounting students. How much assistance should accounting professors provide students for completing homework? Is too much assistance counterproductive? These were some of the questions of interest in a Journal of Accounting Education (Vol. 25, 2007) article. A

Chapter: 8 Problem: 19E

Statistics for Business and Economics 12
Patent infringement case. Chance (Fall 2002) described a lawsuit charging Intel Corp. with infringing on a patent for an invention used in the automatic manufacture of computer chips. In response, Intel accused the inventor of adding material to his patent notebook after the patent was witnessed and

Chapter: 8 Problem: 20E

Statistics for Business and Economics 12
Producer willingness to supply biomass. The conversion of biomass to energy is critical for producing transportation fuels. How willing are producers to supply biomass products such as cereal straw, corn stover, and surplus hay? To answer this question, economists conducted a survey of producers in b

Chapter: 8 Problem: 21E

Statistics for Business and Economics 12
Does rudeness really matter in the workplace? Studies have established that rudeness in the work- place can lead to retaliatory and counterproductive behavior. However, there has been little research on how rude behaviors in?uence a victims task performance. Such a study was conducted and the results

Chapter: 8 Problem: 22E

Statistics for Business and Economics 12
Problem 22E Service without a smile. Service with a smile is a slogan that many businesses adhere to. However, there are some jobs (e.g., those of judges, law enforcement officers, pollsters) that require neutrality when dealing with the public. An organization will typically provide display rules

Chapter: 8 Problem: 23E

Statistics for Business and Economics 12
Problem 23E Is honey a cough remedy? Refer to the Archives of Pediatrics and Adolescent Medicine (Dec. 2007) study of honey as a childrens cough remedy, Exercise 2.30 (p. 61). Children who were ill with an upper respiratory tract infection and their parents participated in the study. Parents were i

Chapter: 8 Problem: 24E

Statistics for Business and Economics 12
Cooling method for gas turbines. Refer to the Journal of Engineering for Gas Turbines and Power (Jan. 2005) study of gas turbines augmented with high-pressure inlet fogging, Exercise 7.40 (p. 378). The researchers classified gas turbines into three categories: traditional, advanced, and aeroderivativ

Chapter: 8 Problem: 25E

Statistics for Business and Economics 12
Problem 25E Ages of self-employed immigrants. Is self-employment for immigrant workers a faster route to economic advancement in the country? This was one of the questions studied in research published in the International Journal of Manpower (Vol. 32, 2011). One aspect of the study involved compar

Chapter: 8 Problem: 26E

Statistics for Business and Economics 12
A paired difference experiment produced the following results: a. Determine the values of z for which the null hypothesis, 1 - 2 = 0, would be rejected in favor of the alternative hypothesis, 1 - 2 < 0. Use ? = .10. b. Conduct the paired difference test described in part a. Draw the appropr

Chapter: 8 Problem: 27E

Statistics for Business and Economics 12
Problem 27E A paired difference experiment yielded nd pairs of observations. In each case, what is the rejection region for testing H0 : d > 2? a. n d = 12, ? = .05 b. n d = 24, ? = .10 c. n d = 4, ? = .025 d. n d = 80, ? = .01

Chapter: 8 Problem: 28E

Statistics for Business and Economics 12
Problem 28E T he data for a random sample of six paired observations are shown in the following table and saved in the LM7_33 file Pair Sample from Population 1 Sample from Population 2 1 7 4 2 3 1 3 9 7 4 6 2 5 4 4 6 8 7 a. Calculate the difference between each pair of o

Chapter: 8 Problem: 29E

Statistics for Business and Economics 12
The data for a random sample of 10 paired observations are shown in the table below. a. If you wish to test whether these data are sufficient to indicate that the mean for population 2 is larger than that for population 1, what are the appropriate null and alternative hypotheses? Define any s

Chapter: 8 Problem: 30E

Statistics for Business and Economics 12
Problem 30E A paired difference experiment yielded the following results: n d = 40 ?d = 468 ?d2 = 6,880 a. Test H0 : d = 10 against Ha : d ? 10, where d = (1 - 2). Use ? = .05. b. Report the p-value for the test you conducted in part a. Interpret the p-value. c. Do you need to assume that the popul

Chapter: 8 Problem: 31E

Statistics for Business and Economics 12
Problem 31E Summer weight-loss camp. Camp Jump Start is an 8-week summer camp for overweight and obese adolescents. Counselors develop a weight-management program for each camper that centers on nutrition education and physical activity. In a study published in Pediatrics (April 2010), the body mas

Chapter: 8 Problem: 32E

Statistics for Business and Economics 12
Problem 32E Performance ratings of government agencies. The U.S. Office of Management and Budget (OMB) requires government agencies to produce annual performance and accounting reports (PARS) each year. A research team at George Mason University evaluated the quality of the PARS for 24 government a

Chapter: 8 Problem: 33E

Statistics for Business and Economics 12
Problem 33E Twinned drill holes. A traditional method of verifying mineralization grades in mining is to drill twinned holes, i.e., the drilling of a new hole, or twin, next to an earlier drill hole. The use of twinned drill holes was investigated in Exploration and Mining Geology (Vol. 18, 2009).

Chapter: 8 Problem: 34E

Statistics for Business and Economics 12
Packaging of a children's health food. Refer to the Journal of Consumer Behaviour (Vol. 10,2011) study of packaging of a children's health food product, Exercise 7.33 (p. 376). Recall that a fictitious brand of a healthy food product sliced apples -was packaged to appeal to children (a smiling cartoo

Chapter: 8 Problem: 35E

Statistics for Business and Economics 12
I am not selling anything surveys. To improve response rates in telephone surveys, interviewers are often instructed by the polling company to state, I am not selling anything at the outset of the call. The effectiveness of the I am not selling anything strategy was investigated in the International

Chapter: 8 Problem: 36E

Statistics for Business and Economics 12
NHTSA new car crash tests. Refer to the National Highway Traffic Safety Administration (NHTSA) crash test data on new cars, saved in the CRASH file. Crash test dummies were placed in the drivers seat and front passengers seat of a new car model, and the car was steered by remote control into a head-o

Chapter: 8 Problem: 37E

Statistics for Business and Economics 12
Problem 37E Taking power naps during work breaks. Lack of sleep costs companies about $18 billion a year in lost productivity, according to the National Sleep Foundation. Companies are waking up to the problem, however. Some even have quiet rooms available for study or sleep. Power naps are in vogu

Chapter: 8 Problem: 38E

Statistics for Business and Economics 12
Problem 38E Acidity of mouthwash. Acid has been found to be a primary cause of dental caries (cavities). It is theorized that oral mouthwashes contribute to the development of caries due to the antiseptic agent oxidizing into acid over time. This theory was tested in the Journal of Dentistry, Oral

Chapter: 8 Problem: 39E

Statistics for Business and Economics 12
Problem 39E Testing electronic circuits. Japanese researchers have developed a compression/depression method of testing electronic circuits based on Huffman coding (IEICE Transactions on Information & Systems, Jan. 2005). The new method is designed to reduce the time required for input decompressio

Chapter: 8 Problem: 40E

Statistics for Business and Economics 12
Problem 40E Impact of red light cameras on car crashes. To combat red-light-running crashesthe phenomenon of a motorist entering an intersection after the traffic signal turns red and causing a crashmany states are adopting photored enforcement programs. In these programs, red light cameras install

Chapter: 8 Problem: 41E

Statistics for Business and Economics 12
Problem 41E Evaluating a new drug. Merck Research Labs conducted an experiment to evaluate the effect of a new drug using the single-T swim maze. Nineteen impregnated dam rats were captured and allocated a dosage of 12.5 milligrams of the drug. One male and one female rat pup were randomly selected

Chapter: 8 Problem: 42E

Statistics for Business and Economics 12
Problem 42E Alcoholic fermentation in wines. Determining alcoholic fermentation in wine is critical to the wine-making process. Must/wine density is a good indicator of the fermentation point, since the density value decreases as sugars are converted into alcohol. For decades, winemakers have measu

Chapter: 8 Problem: 43E

Statistics for Business and Economics 12
Problem 43E Consider making an inference about p1 - p2, where there are x1 successes in n1 binomial trials and x2 successes in n2 binomial trials. a. Describe the distributions of x1 and x2. b. Explain why the Central Limit Theorem is important in finding an approximate distribution for

Chapter: 8 Problem: 44E

Statistics for Business and Economics 12
Problem 44E For each of the following values of ?, find the values of z for which H0 : (p1 - p2) = 0 would be rejected in favor of Ha : (p1 - p2) < 0. a. ? = .01 : b. ? = .025 c. ? = .05 : d. ? = .10

Chapter: 8 Problem: 45E

Statistics for Business and Economics 12
Problem 45E In each case, determine whether the sample sizes are large enough to conclude that the sampling distribution of is approximately normal. a. n 1 = 12, n2 = 14, = .42, = .57 b. n 1 = 12, n2 = 14, = .92, = .86 c. n 1 = n2 = 30, = .70, = .73 d. n 1 = 100, n2 = 250, =

Chapter: 8 Problem: 46E

Statistics for Business and Economics 12
Problem 46E Construct a 95% confidence interval for (p1 - p2) in each of the following situations: a. n1 = 400, p?1 = .65; n2 = 400, p?2 = .58 ________________ b. n1 = 180, p?1 = .31; n2 = 250, p?2 = .25 ________________ c. n1 = 100, p?1 = .46; n2 = 120, p?2 = .61

Chapter: 8 Problem: 47E

Statistics for Business and Economics 12
Problem 47E Independent random samples, each containing 800 observations, were selected from two binomial populations. The samples from populations 1 and 2 produced 320 and 400 successes, respectively. a. Test H0 : (p1 - p2) = 0 against Ha : (p1 - p2) 7 0. Use a = .05. b. Test H0 : (p1 - p2) = 0 ag

Chapter: 8 Problem: 48E

Statistics for Business and Economics 12
Problem 48E Random samples of size n1 = 55 and n2 = 65 were drawn from populations 1 and 2, respectively. The samples yielded = .7 and = .6. Test H0 : (p1 - p2) = 0 against Ha : (p1 - p2) > 0 using ? = .05.

Chapter: 8 Problem: 49E

Statistics for Business and Economics 12
The winners curse in auction bidding. In auction bidding, the winners curse is the phenomenon of the winning (or highest) bid price being above the expected value of the item being auctioned. The Review of Economics and Statistics (Aug. 2001) published a study on whether bid experience impacts the li

Chapter: 8 Problem: 50E

Statistics for Business and Economics 12
Is steak your favorite barbeque food? July is National Grilling Month in the United States. On July 1, 2008, The Harris Poll #70 reported on a survey of Americans grilling preferences. When asked about their favorite food prepared on a barbeque grill, 662 of 1,250 randomly sampled Democrats preferred

Chapter: 8 Problem: 51E

Statistics for Business and Economics 12
Producer willingness to supply biomass. Refer to the Biomass and Energy (Vol. 36, 2012) study of the willingness of producers to supply biomass products such as surplus hay, Exercise 8.20 (p. 436). Recall that independent samples of Missouri producers and Illinois producers were surveyed. Another asp

Chapter: 8 Problem: 52E

Statistics for Business and Economics 12
Problem 52E Planning-habits survey. American Demographics (Jan. 2002) reported the results of a survey on the planning habits of men and women. In response to the question What is your preferred method of planning and keeping track of meetings appointments, and deadlines? 56% of the men and 46% of

Chapter: 8 Problem: 53E

Statistics for Business and Economics 12
Hospital administration of malaria patients. One of the most serious health problems in India is malaria. Consequently, Indian hospital administrators must have the resources to treat the high volume of malaria patients that are admitted. Research published in the National Journal ofCommunity Medicin

Chapter: 8 Problem: 54E

Statistics for Business and Economics 12
Electronic vs. printed surveys. The rapid evolution of computer hardware and software has made it easy for businesses to conduct computer-based and Web-based (i.e., electronic) surveys. Professors at Michigan State and DePaul Universities collaborated on a study designed to compare the response rates

Chapter: 8 Problem: 55E

Statistics for Business and Economics 12
Salmonella in produce. Salmonella is the most common type of bacterial food-borne illness in the United States. How prevalent is salmonella in produce grown in the major agricultural region of Monterey, California? Researchers from the U.S. Department of Agriculture (USDA) conducted tests for salmone

Chapter: 8 Problem: 56E

Statistics for Business and Economics 12
Problem 56E Angioplastys benefits challenged. Each year, more than 1 million heart patients undergo an angioplasty. The benefits of an angioplasty were challenged in a recent study of 2,287 patients (2007 Annual Conference of the American College of Cardiology, New Orleans). All the patients had su

Chapter: 8 Problem: 57E

Statistics for Business and Economics 12
Entrepreneurial careers of MBA alumni. Are African American MBA students more likely to begin their careers as entrepreneurs than white MBA students? This was a question of interest to the Graduate Management Admission Council (GMAC). GMAC Research Reports (Oct. 3, 2005) published the results of a su

Chapter: 8 Problem: 58E

Statistics for Business and Economics 12
Problem 58E Predicting software defects. Refer to the PROMISE Software Engineering Repository data on 498 modules of software code written in C language for a NASA spacecraft instrument, saved in the file. (See Exercise 3.76, p. 168) Recall that the software code in each module was evaluated for de

Chapter: 8 Problem: 59E

Statistics for Business and Economics 12
Problem 59E Food craving study. Do you have an insatiable craving for chocolate or some other food? Because many North Americans apparently do, psychologists are designing scientific studies to examine the phenomenon. According to the New York Times (Feb. 22, 1995), one of the largest studies of fo

Chapter: 8 Problem: 60E

Statistics for Business and Economics 12
Problem 60E Religious symbolism in TV commercials. Gonzaga University professors conducted a study of television commercials and published their results in the Journal of Sociology, Social Work and Social Welfare (Vol. 2, 2008). The key research question was: Do television advertisers use religious

Chapter: 8 Problem: 61E

Statistics for Business and Economics 12
Assuming that \(n_1 = n_2\), find the sample sizes needed to estimate (\(p_1 - p_2\)) for each of the following situations: a. Margin of error = .01 with 99% confidence. Assume that \(p_1\ \approx\ .4\) and \(p_2\ \approx\ .7\). b. A 90% confidence interval of width .05. Assume that there is

Chapter: 8 Problem: 62E

Statistics for Business and Economics 12
Problem 62E Find the appropriate values of n1 and n2 (assume n1 = n2) needed to estimate (?1 - ?2) for each of the following situations: a. A margin of error equal to 3.2 with 95% confidence. From prior experience it is known that ?1 ? 15 and ?2 ?17. b. A margin of error equal to 8 with 99% confide

Chapter: 8 Problem: 63E

Statistics for Business and Economics 12
Problem 63E Suppose you want to estimate the difference between two population means correct to within 1.8 with a 95% confidence interval. If prior information suggests that the population variances are approximately equal to ?12 = ?2 2 = 14 and you want to select independent random samples of equa

Chapter: 8 Problem: 64E

Statistics for Business and Economics 12
Problem 64E Enough money has been budgeted to collect independent random samples of size n1 = n2 = 100 from populations 1 and 2 to estimate (?1 - ?2). Prior information indicates that ?1 = ?2 = 10. Have sufficient funds been allocated to construct a 90% confidence interval for (?1 - ? 2) of width 5

Chapter: 8 Problem: 65E

Statistics for Business and Economics 12
Problem 65E Last name and acquisition timing. Refer to the Journal of Consumer Research (August 2011) study of the last name effect in acquisition timing, Exercise 8.13 (p. 433). Recall that the mean response times (in minutes) to acquire basketball tickets were compared for two groups of MBA stude

Chapter: 8 Problem: 66E

Statistics for Business and Economics 12
Homework assistance for accounting students. Refer to the Journal of Accounting Education (Vol. 25, 2007) study of providing homework assistance to accounting students, Exercise 8.18 (p. 435). Recall that one group of students was given a completed homework solution and another group was given only c

Chapter: 8 Problem: 67E

Statistics for Business and Economics 12
Problem 67E Electronic vs. printed surveys. Refer to the Decision Line (July 2001) study designed to compare the response rates of electronic surveys and traditional print surveys, Exercise 8.54 (p. 454). Recall that the two surveys were developed for customers who had purchased products over the I

Chapter: 8 Problem: 68E

Statistics for Business and Economics 12
Problem 68E Conducting a political poll. A pollster wants to estimate the difference between the proportions of men and women who favor a particular national candidate using a 90% confidence interval of width .04. Suppose the pollster has no prior information about the proportions. If equal numbers

Chapter: 8 Problem: 69E

Statistics for Business and Economics 12
Problem 69E Life expectancies of working women and housewives. Is housework hazardous to your health? A study in Public Health Reports compared the life expectancies of 25-yearold white women in the labor force to those who are housewives. How large a sample would have to be taken from each group i

Chapter: 8 Problem: 70E

Statistics for Business and Economics 12
Users of home shopping services. All cable companies carry at least one home shopping channel. Who uses these home shopping services? Are the shoppers primarily men or women? Suppose you want to estimate the difference in the proportions of men and women who say they have used or expect to use televi

Chapter: 8 Problem: 71E

Statistics for Business and Economics 12
Problem 71E Angioplastys benefits challenged. Refer to the study of patients with substantial blockage of the arteries presented at the 2007 Annual Conference of the American College of Cardiology, Exercise 8.56 (p. 455). Recall that half the patients were randomly assigned to get an angioplasty an

Chapter: 8 Problem: 72E

Statistics for Business and Economics 12
Average housing space per person. Even though Japan is an economic superpower, Japanese workers are in many ways worse off than their U.S. and European counterparts. For example, the estimated average housing space per person (in square feet) is 645 in the United States but only 344 in Japan (Diawa H

Chapter: 8 Problem: 73E

Statistics for Business and Economics 12
Problem 73E Use Tables V, VI, VII, and VIII in Appendix D to find each of the following F-values: a. F .05 where v1 = 9 and v2 = 6 b. F .01 where v1 = 18 and v2 = 14 c. F.025 where v1 = 11 and v2 = 4 d. F.10 where v1 = 20 and v2 = 5

Chapter: 8 Problem: 74E

Statistics for Business and Economics 12
Problem 74E Given v1 and v2, find the following probabilities: a. v1 = 2, v2 = 30, b. v1 = 24, v2 = 10, c. v1 = 7, v2 = 1, d. v1 = 40, v2 = 40,

Chapter: 8 Problem: 75E

Statistics for Business and Economics 12
Problem 75E For each of the following cases, identify the rejection region that should be used to test against . Assume v1 = 30 and v2 = 20. a. ? = .10 : b. ? = .05 c. ? = .025 : d. ? = .01

Chapter: 8 Problem: 76E

Statistics for Business and Economics 12
For each of the following cases, identify the rejection region that should be used to test \(H_{0}: \sigma_{1}^{2}=\sigma_{2}^{2}\) against \(H_{\mathrm{a}}: \sigma_{1}^{2} \neq \sigma_{2}^{2}\). Assume \(\nu_{1}=10\) and \(\nu_{2}=12\). a. \(\alpha=.20\) b. \(\alpha=.10\) c. \(\alpha=.05

Chapter: 8 Problem: 77E

Statistics for Business and Economics 12
Problem 77E Specify the appropriate rejection region for testing in each of the following situations:

Chapter: 8 Problem: 78E

Statistics for Business and Economics 12
Problem 78E Independent random samples were selected from each of two normally distributed populations, n1 = 12 from population 1 and n2 = 27 from population 2. The means and variances for the two samples are shown in the table. a. Test the null hypothesis against the alternative hypothesis

Chapter: 8 Problem: 79E

Statistics for Business and Economics 12
Problem 79E Independent random samples were selected from each of two normally distributed populations, n1 = 6 from population1 and n2 = 5 from population 2. The data are shown in the table. a. Test against . Use ? = .01. b. Find and interpret the approximate p-value of the test.

Chapter: 8 Problem: 80E

Statistics for Business and Economics 12
Lobster trap placement. Refer to the Bulletin of Marine Science (April 2010) study of lobster trap placement, Exercise 8.12 (p. 433). The data are repeated here (next column). You used the small-sample t-statistic to form a confidence interval for the difference between the mean trap-spacing measurem

Chapter: 8 Problem: 81E

Statistics for Business and Economics 12
Childrens recall of TV ads. Refer to the Journal of Advertising (Spring 2006) study of childrens recall of television commercials, Exercise 8.15 (p. 434). You used a smallsample t-test to test the null hypothesis \(H_0:(\mu_1-\mu_2)=0\), where \(\mu_1\) = mean number of ads recalled by children in th

Chapter: 8 Problem: 82E

Statistics for Business and Economics 12
Problem 82E 8.82 Mental health of workers and the unemployed. A study in the Journal of Occupational and Organizational Psychology investigated the relationship of employment status and mental health. A sample of working and unemployed people was selected, and each person was given a mental health

Chapter: 8 Problem: 83E

Statistics for Business and Economics 12
Problem 83E Drug content assessment. Refer to Exercise 8.16 (p. 434) and the Analytical Chemistry (Dec. 15, 2009) study in which scientists used high-performance liquid chromatography to determine the amount of drug in a tablet. Recall that 25 tablets were produced at each of two different, indepen

Chapter: 8 Problem: 84E

Statistics for Business and Economics 12
Patent infringement case. ?Refer to the Chance (Fall 2002) description of a patent infringement case against Intel Corp., Exercise 8.19 (p. 435). The zinc measurements for three locations on the original inventors notebook on a text line, on a witness line, and on the intersection of the witness and

Chapter: 8 Problem: 85E

Statistics for Business and Economics 12
Problem 85E Analyzing human inspection errors. Tests of product quality using human inspectors can lead to serious inspection error problems (Journal of Quality Technology). To evaluate the performance of inspectors in a new company, a quality manager had a sample of 12 novice inspectors evaluate 2

Chapter: 8 Problem: 86E

Statistics for Business and Economics 12
Problem 86E Cooling method for gas turbines. Refer to the Journal of Engineering for Gas Turbines and Power (Jan. 2005) study of gas turbines augmented with high-pressure inlet fogging, Exercise 8.24 (p. 437). Heat rate data (kilojoules per kilowatt per hour) for each of three types of gas turbines

Chapter: 8 Problem: 87E

Statistics for Business and Economics 12
Problem 87E Just-in-time deliveries from factories to foxholes. Following the initial Persian Gulf War, the Pentagon changed its logistics processes to be more corporate-like. The extravagant just-in-case mentality was replaced with just-in-time systems. Emulating FedEx and United Parcel Service, d

Chapter: 8 Problem: 88E

Statistics for Business and Economics 12
Is honey a cough remedy? Refer to the Archives of Pediatrics and Adolescent Medicine (Dec. 2007) study of honey as a childrens cough remedy, Exercise 8.23 (p. 437). The data (cough improvement scores) for the 33 children in the DM dosage group and the 35 children in the honey dosage group are reprodu

Chapter: 8 Problem: 89SE

Statistics for Business and Economics 12
Problem 89SE List the assumptions necessary for each of the following inferential techniques: a. Large-sample inferences about the difference (?1 - ?2) between population means using a two-sample z-statistic b. Small-sample inferences about (?1 - ?2) using an independent samples design and a two-sa

Chapter: 8 Problem: 90SE

Statistics for Business and Economics 12
Problem 90SE Two independent random samples were selected from normally distributed populations with means and variances and , respectively. The sample sizes, means, and variances are shown in the following table. a. Test against . Use a = .05. b. Would you be willing to use a small sam

Chapter: 8 Problem: 91SE

Statistics for Business and Economics 12
Problem 91SE Independent random samples were selected from two normally distributed populations with means m1 and m2, respectively. The sample sizes, means, and variances are shown in the following table: a. Test H0: (?1 ?2) = 0 against Ha: (?1 ?2)> 0. Use ? = .05. ________________ b. Form a 99

Chapter: 8 Problem: 92SE

Statistics for Business and Economics 12
Problem 92SE Independent random samples were selected from two binomial populations. The sizes and number of observed successes for each sample are shown in the following table. a. Test H0: ( p1 - p2) = 0 against Ha: ( p1 - p2) < 0. Use ? = .10. b. Form a 95% confidence interval for ( p1 - p2).

Chapter: 8 Problem: 93SE

Statistics for Business and Economics 12
Problem 93SE Two independent random samples are taken from two populations. The results of these samples are summarized in the following table: ________________ a. Form a 90% confidence interval for (?1 ?2). ________________ b. Test H0: (?1 ?2) = 0 against Use ? = .01. ________________ c.

Chapter: 8 Problem: 94SE

Statistics for Business and Economics 12
Problem 94SE A random sample of nine pairs of observations is recorded on two variables x and y . The data are shown in the following table and saved in the LM7_119 file. Do the data provide sufficient evidence to indicate that the probability distribution for x is shifted to the right of that for

Chapter: 8 Problem: 95SE

Statistics for Business and Economics 12
Problem 95SE Determining the target parameter. For each of the following studies, give the parameter of interest and state any assumptions that are necessary for the inferences to be valid. a. To investigate a possible link between jet lag and memory impairment, a University of Bristol (England) ne

Chapter: 8 Problem: 96SE

Statistics for Business and Economics 12
Problem 96SE Financial incentives for college students. A study reported in Inside Higher Education News (May 22, 2006) found that financial incentives can improve low-income college students grades and retention. As part of their Opening Doors program, a Louisiana community college offered to pay

Chapter: 8 Problem: 97SE

Statistics for Business and Economics 12
Problem 97SE Rating service at five-star hotels. A study published in The Journal of American Academy of Business, Cambridge (March 2002) examined whether the perception of service quality at five-star hotels in Jamaica differed by gender. Hotel guests were randomly selected from the lobby and rest

Chapter: 8 Problem: 98SE

Statistics for Business and Economics 12
Problem 98SE Hull failures of oil tankers. Refer to the Marine Technology (Jan. 1995) study of major oil spills from tankers and carriers, Exercise 2.159 (p. 117). The data for the 42 recent spills are saved in the accompanying file. a. Construct a 90% confidence interval for the difference between

Chapter: 8 Problem: 99SE

Statistics for Business and Economics 12
Financial incentives for college students. Do students who play virtual-reality educational software games perform better in school? If so, software designers will use this information to create more attractive and motivating educational software. In a study published in Educational Technology & Soci

Chapter: 8 Problem: 100SE

Statistics for Business and Economics 12
Problem 100SE Durability of shock absorbers. A manufacturer of automobile shock absorbers was interested in comparing the durability of its shocks with that of the shocks produced by its biggest competitor. To make the comparison, one of the manufacturers and one of the competitors shocks were rand

Chapter: 8 Problem: 101SE

Statistics for Business and Economics 12
Problem 101SE Life expectancy of Oscar winners. Does winning an Academy of Motion Picture Arts and Sciences award lead to long-term mortality for movie actors? In an article in the Annals of Internal Medicine (May 15, 2001), researchers sampled 762 Academy Award winners and matched each one with an

Chapter: 8 Problem: 102SE

Statistics for Business and Economics 12
Problem 102SE Diamonds sold at retail. Refer to the data for 308 diamonds saved in the file. Two quantitative variables in the data set are number of carats and selling price. One of the qualitative variables is the independent certification body that assessed each of the stones. Three certificatio

Chapter: 8 Problem: 103SE

Statistics for Business and Economics 12
Problem 103SE Ages of cable TV shoppers. Refer to the International Association for Time Use Research study on cable TV viewers who purchase items from one of the home shopping channels, Exercise 7.142 (p. 412). The 1,600 sampled viewers described their motivation for watching cable TV shopping net

Chapter: 8 Problem: 104SE

Statistics for Business and Economics 12
Problem 104SE Career success expectations. In evaluating the usefulness and validity of a questionnaire, researchers often pretest the questionnaire on different independently selected samples of respondents. Knowledge of the differences and similarities of the samples and their respective populati

Chapter: 8 Problem: 105SE

Statistics for Business and Economics 12
Likelihood of getting a routine medical checkup. Who is more likely to get a routine medical checkupemployed or unemployed people? To answer this question, a team of physicians and public health professors collected data on a sample of over 2,200 individuals (American Journal of Public Health, Jan. 2

Chapter: 8 Problem: 106SE

Statistics for Business and Economics 12
Problem 106SE Turnover rates in the United States and Japan. High job turnover rates are often associated with high product defect rates because high turnover rates mean more inexperienced workers who are unfamiliar with the companys product lines (Stevenson, Production/Operations Management, 2000)

Chapter: 8 Problem: 107SE

Statistics for Business and Economics 12
Problem 107SE Cell phone usage differs by gender. The role of the cell phone in modern life was investigated by a Pew Internet & American Life Project (April 2006) survey. A total of 1,286 cell phone users were interviewed in the sample. One of the objectives was to compare male and female cell pho

Chapter: 8 Problem: 108SE

Statistics for Business and Economics 12
Sampling plan for a movie promotion. Advertising companies often try to characterize the average user of a clients product so ads can be targeted at particular segments of the buying community. A new movie is about to be released, and the advertising company wants to determine whether to aim the ad c

Chapter: 8 Problem: 109SE

Statistics for Business and Economics 12
Problem 109SE Comparing purchasers and nonpurchasers of toothpaste. Marketing strategists would like to predict consumer response to new products and their accompanying promotional schemes. Consequently, studies that examine the differences between buyers and nonbuyers of a product are of interest.

Chapter: 8 Problem: 110SE

Statistics for Business and Economics 12
Problem 110SE Killing moths with carbon dioxide. A University of South Florida biologist conducted an experiment to determine whether increased levels of carbon dioxide kill leaf-eating moths (USF Magazine, Winter 1999). Moth larvae were placed in open containers filled with oak leaves. Half the con

Chapter: 8 Problem: 111SE

Statistics for Business and Economics 12
Problem 111SE Racial profiling by the LAPD. Racial profiling is a term used to describe any police action that relies on ethnicity rather than behavior to target suspects engaged in criminal activities. Does the Los Angeles Police Department (LAPD) invoke racial profiling in stops and searches of L

Chapter: 8 Problem: 112SE

Statistics for Business and Economics 12
State SAT scores. Refer to Exercise 2.27 (p. 60) and the data on average math SAT scores for each of the 50 states and District of Columbia for the years 2001 and 2011. The data are saved in the file. (The first five observations and last two observations in the data set are shown in the table below.

Chapter: 8 Problem: 113SE

Statistics for Business and Economics 12
Rat damage to sugarcane fields. Poisons are used to prevent rat damage in sugarcane fields. The U.S. Department of Agriculture is investigating whether the rat poison should be located in the middle of the field or on the outer perimeter. One way to answer this question is to determine where the grea

Chapter: 8 Problem: 114SE

Statistics for Business and Economics 12
Environmental impact study. Some power plants are located near rivers or oceans so that the available water can be used for cooling the condensers. Suppose that, as part of an environmental impact study, a power company wants to estimate the difference in mean water temperature between the discharge

Chapter: 8 Problem: 115SE

Statistics for Business and Economics 12
Instrument precision. When new instruments are developed to perform chemical analyses of products (food, medicine, etc.), they are usually evaluated with respect to two criteria: accuracy and precision. Accuracy refers to the ability of the instrument to identify correctly the nature and amounts of a

Chapter: 8 Problem: 116SE

Statistics for Business and Economics 12
Computer-mediated communication study. Computer-mediated communication (CMC) is a form of interaction that heavily involves technology (e.g., instant messaging, e-mail). A study was conducted to compare relational intimacy in people interacting via CMC to people meeting face-to-face (FTF) (Journal of

Chapter: 8 Problem: 117SE

Statistics for Business and Economics 12
Computer-mediated communication study (contd). Refer to Exercise 8.116. The researchers also hypothesized that the mean relational intimacy score for participants in the group would significantly increase between the first and third meetings, but the difference between the first and third meetings wo

Chapter: 8 Problem: 118SE

Statistics for Business and Economics 12
Positive spillover effects from self-managed work teams. To improve quality, productivity, and timeliness, many American industries employ self-managed work teams (SMWTs). A team typically consists of 5 to 15 workers who are collectively responsible for making decisions and performing all tasks relat

Chapter: 8 Problem: 119SE

Statistics for Business and Economics 12
Problem 119SE Impact of gender on advertising. How does gender affect the type of advertising that proves to be most effective? An article in the Journal of Advertising Research (May/June 1990) makes reference to numerous studies that conclude males tend to be more competitive with others than with

Chapter: 8 Problem: 120SE

Statistics for Business and Economics 12
Salaries of postgraduates. Refer to the Economics of Education Review (Vol. 21, 2002) study of the relationship between education level and earnings, Exercise 7.46 (p. 379). A National Adult Literacy Survey revealed that males with a postgraduate degree had a sample mean salary of $61,340 (with stand

Chapter: 8 Problem: 121SE

Statistics for Business and Economics 12
Gambling in public high schools. With the rapid growth in legalized gambling in the United States, there is concern that the involvement of youth in gambling activities is also increasing. University of Minnesota Professor Randy Stinchfield compared the rates of gambling among Minnesota public school

Chapter: 8 Problem: 122SE

Statistics for Business and Economics 12
Problem 122SE CareerBank.com annual salary survey. CareerBank.com conducts an annual salary survey of accounting, finance, and banking professionals. For one survey, data were collected for 2,800 responses submitted online by professionals across the country who voluntarily responded to CareerBank.c

Chapter: 8 Problem: 123SE

Statistics for Business and Economics 12
Facility layout study. Facility layout and material flow path design are major factors in the productivity analysis of automated manufacturing systems. Facility layout is concerned with the location arrangement of machines and buffers for work-in-process. Flowpath design is concerned with the directi

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