New Semester
Started
Get
50% OFF
Study Help!
--h --m --s
Claim Now
Question Answers
Textbooks
Find textbooks, questions and answers
Oops, something went wrong!
Change your search query and then try again
S
Books
FREE
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Tutors
Online Tutors
Find a Tutor
Hire a Tutor
Become a Tutor
AI Tutor
AI Study Planner
NEW
Sell Books
Search
Search
Sign In
Register
study help
mathematics
statistics
Statistics For Management And Economics Abbreviated 10th Edition Gerald Keller - Solutions
Some traffic experts believe that the major cause of highway collisions is the differing speeds of cars. That is, when some cars are driven slowly while others are driven at speeds well in excess of the speed limit, cars tend to congregate in bunches, increasing the probability of accidents. Thus,
The job placement service at a university observed the not unexpected result of the variance in marks and work experience of the university’s graduates: Some graduates received numerous offers whereas others received far fewer. To learn more about the problem, a survey of 90 recent graduates was
One problem facing the manager of maintenance departments is when to change the bulbs in streetlamps. If bulbs are changed only when they burn out, it is quite costly to send crews out to change only one bulb at a time. This method also requires someone to report the problem and, in the meantime,
Home blood-pressure monitors have been on the market for several years. This device allows people with high blood pressure to measure their own and determine whether additional medication is necessary. Concern has been expressed about inaccurate readings. To judge the severity of the problem a
a. In a random sample of 200 observations, we found the proportion of successes to be 48%. Estimate with 95% confidence the population proportion of successes.b. Repeat part (a) with n = 500.c. Repeat part (a) with n = 1000.d. Describe the effect on the confidence interval estimate of increasing
a. The proportion of successes in a random sample of 400 was calculated as 50%. Estimate the population proportion with 95% confidence.b. Repeat part (a) with p̂ = 33%.c. Repeat part (a) with p̂ = 10%.d. Discuss the effect on the width of the confidence interval estimate of reducing the sample
a. Calculate the p-value of the test of the following hypotheses given that p̂ = .63 and n = 100:H0: p = .60H1: p > .60b. Repeat part (a) with n = 200.c. Repeat part (a) with n = 400.d. Describe the effect on the p-value of increasing the sample size.
a. A statistics practitioner wants to test the following hypotheses:H0: p = .70H1: p > .70A random sample of 100 produced p̂ = .73. Calculate the p-value of the test.b. Repeat part (a) with p̂ = .72.c. Repeat part (a) with p̂ = .71.d. Describe the effect on the z-statistic and its p-value of
Suppose that you used the sample size calculated in Exercise 12.86 and found p̂ = .75.a. Estimate the population proportion with 90% confidence.b. Is this the result you expected? Explain.c. If you were hired to conduct this analysis, would the person who hired you be satisfied with the interval
Suppose that you used the sample size calculated in Exercise 12.89 and found p̂ = .92.a. Estimate the population proportion with 90% confidence.b. Is this the result you expected? Explain.c. If you were hired to conduct this analysis, would the person who hired you be satisfied with the interval
Suppose that you used the sample size calculated in Exercise 12.89 and found p̂ = .5.a. Estimate the population proportion with 90% confidence.b. Is this the result you expected? Explain.c. If you were hired to conduct this analysis, would the person who hired you be satisfied with the interval
In some states, the law requires drivers to turn on their headlights when driving in the rain. A highway patrol officer believes that less than one-quarter of all drivers follow this rule. As a test, he randomly samples 200 cars driving in the rain and counts the number whose headlights are turned
Has the recent drop in airplane passengers resulted in better on-time performance? Before the recent downturn one airline bragged that 92% of its flights were on time. A random sample of 165 flights completed this year reveals that 153 were on time. Can we conclude at the 5% significance level that
In Chapter 6, we discussed how an understanding of probability allows one to properly interpret the results of medical screening tests. The use of Bayes’s Law requires a set of prior probabilities, which are based on historical records. Suppose that a physician wanted to estimate the probability
Spam is of concern to anyone with an e-mail address. Several companies offer protection by eliminating spam e-mails as soon as they hit an inbox. To examine one such product, a manager randomly sampled his daily e-mails for 50 days after installing spam software. A total of 374 e-mails were
A management professor was in the process of investigating the relationship between education and managerial level achieved. The source of his data was a survey of 385 CEOs of medium and large companies. He discovered that there was only 1 CEO who did not have at least one university degree.
A national survey conducted by Pew Research asked a random sample of 974 American adults how they felt about doing their taxes. The responses are: 1 = Love it, 2 = Like it, 3 = Neither like nor dislike it, 4 = Dislike it, 5 = Hate it. There are 234,564,000 American adults. Estimate with 95%
According to the Internal Revenue Service (IRS) in 2009 the top 5% of American income earners earned more than $153,542 and the top 1% earned more than $388,806. The top 1% pays slightly more than 40% of all federal income taxes.To determine whether Americans are aware of these figures Investor’s
The results of an annual Claimant Satisfaction Survey of policyholders who have had a claim with State Farm Insurance Company revealed a 90% satisfaction rate for claim service. To check the accuracy of this claim, a random sample of State Farm claimants was asked to rate whether they were
An important decision faces Christmas holiday celebrators: buy a real or artificial tree? A sample of 1,508 male and female respondents 18 years of age and over was interviewed. Respondents were asked whether they preferred a real (1) or artificial (2) tree. If there are 6 million Canadian
A professor of business statistics recently adopted a new textbook. At the completion of the course, 100 randomly selected students were asked to assess the book. The responses are as follows:Excellent (1), Good (2), Adequate (3), Poor (4)The results are stored using the codes in parentheses. Do
Refer to Exercise 12.112. Do the data allow us to conclude that more than 90% of all business students would rate it as at least adequate?
Refer to the chapter-opening example.Estimate with 95% confidence the number of Americans 18 to 49 years old who were tuned to the American Idol.12.115 Xr12-115 12.116 Xr12-116
According to the American Contract Bridge League (ACBL) bridge hands that contain two 4-card suits, one 3-card suit and one 2-card suit (4-4-3-2) occur with 21.55% probability. Suppose that a bridge-playing statistics profess with much too much time on his hands tracked the number of hands over a
Chlorofluorocarbons (CFCs) are used in air conditioners. However, CFCs damage the ozone layer, which protects us from the sun’s harmful rays. As a result many jurisdictions have banned the production and use of CFCs. The latest jurisdiction to do so is the province of Ontario, which has banned
GSS2012* Estimate with 95% confidence the number of American adults in 2012 who did not finish high school (DEGREE: 0 = Left high school, 1 = High school, 2 = Junior college, 3 = Bachelor’s degree, 4 = Graduatedegree).
a. Estimate with 90% confidence the number of American adults who were working full time.b. Estimate with 95% confidence the number of American adults who were unemployed, or laid off. (WRKSTAT: 1 = Working full time, 2 = Working part time, 3 = Temporarily not working, 4 = Unemployed, laid off, 5 =
Can we infer that more than 10% of Americans are self-employed (WRKSLF: 1 = Self employed, 2 = Someone else)?
Are you employed by the federal, state, or local government, or by a private employer (WRK-GOVT)? 1 = Government, 2 = Private. Estimate with 90% confidence the number of Americans who work for government.
Estimate with 99% confidence the number of Americans who support the Republican party (PARTYID3: 1 = Democrat, 2 = Independent, 3 = Republican).
Among Democratic and Republican party supporters only can we conclude that there are less Republican party supporters than Democratic party supporters (PARTYID3: 1 = Democrat, 2 = Independent, 3 = Republican, 7 = other)?
Estimate with 95% confidence the number of Americans who consider themselves conservative (POLVIEW3: 1 = liberal, 2 = moderate, 3 = conservative).
Among conservatives and liberals only is there sufficient evidence to conclude that there are more conservatives (POLVIEWS3: 1 = liberal, 2 = moderate, 3 = conservative)?
Estimate with 95% confidence the number of American adults who consider themselves political independents (PARTYID3: 1 = Democrat, 2 = Independent, 3 = Republican).
Estimate with 95% confidence the number of Americans who consider themselves moderates (POLVIEW3: 1 = liberal, 2 = moderate, 3 = conservative).
Among conservatives and moderates only is there sufficient evidence to conclude that there are more moderates than conservatives (POLVIEW3: 1 = liberal, 2 = moderate, 3 = conservative)?
Estimate with 95% confidence the number of American adults in 2012 who finished high school only (DEGREE: 0 = Left high school, 1 = High school, 2 = Junior college, 3 = Bachelor’s degree, 4 = Graduate degree)
Estimate with 95% confidence the number of American adults who work for themselves (WRKSLF: 1 = Self employed, 2 = Someone else).
Estimate with 90% confidence the number of American adults who were working part time (WRKSTAT: 1 = Working full time, 2 = Working part time, 3 = Temporarily not working, 4 = Unemployed, laid off, 5 = Retired, 6 = School, 7 = Keeping house, 8 = Other).
Estimate with 95% confidence the number of American adults who work in the private sector (WRKGOVT)? 1 = Government, 2 = Private).
Is there sufficient evidence to conclude that more than 33% of American adults have at least a Bachelor’s degree (DEGREE: 0 = Left high school, 1 = High school, 2 = Junior college, 3 = Bachelor’s degree, 4 = Graduate degree)?
Is there sufficient evidence to infer that in 2008 more Americans see themselves as Democrats than Republicans (PARTY3: 1 = Democrat, 2 = Republican, 3 = Independent)?
Can we infer that in 2008 more Americans perceived themselves as conservative as liberal (LIBCON3: 1 = liberal, 2 = moderate 3 = conservative)?
ANES2008* Estimate with 95% confidence the number of American adults who do not have health insurance (HEALTH: 1 = Yes, 5 = No).
A new credit card company is investigating various market segments to determine whether it is profitable to direct its advertising specifically at each one. One of the market segments is composed of Hispanic people. The latest census indicates that there are 31,669,000 Hispanic adults (18 and over)
A California university is investigating expanding its evening programs. It wants to target people between 25 and 55 years old who have completed high school but did not complete college or university. To help determine the extent and type of offerings, the university needs to know the size of its
The JC Penney department store chain segments the market for women’s apparel by its identification of values. The three segments are:1. Conservative2. Traditional3. ContemporaryQuestionnaires about personal and family values are used to identify which segment a woman falls into. Suppose that the
Most life insurance companies are leery about offering policies to people over 64. When they do the premiums must be high enough to overcome the predicted length of life. The president of one life insurance company was thinking about offering special discounts to Americans over 64 who held
An advertising company was awarded the contract to design advertising for Rolls Royce auto-mobiles. An executive in the firm decided to pitch the product not only to the affluent in the United States but also to those who think they are in the top 1% of income earners in the country. A survey was
Suppose the survey in the previous exercise also asked those who were not in the top 1% whether they believed that within 5 years they would be in the top 1% (1 = will not be in top 1% within 5 years and 2 = will be in top 1% within 5 years). Estimate with 95% confidence the number of Americans who
The National Hockey League’s Florida Panthers play in the BB&T center. The cost of parking is $20. However, Lexus occasionally pays the cost by offering free parking to drivers of Lexus cars. A statistician wanted to estimate the cost of this program. He randomly sampled 300 cars entering the
Hazardous materials are constantly being around the country. To help determine how dangerous these events are a statistics practitioner recorded the distances of a random sample of trucks, trains, airplanes, and boats carrying explosives. Estimate with 95% confidence the mean distance.
One of the issues that came up in a recent municipal election was the high cost of housing. A candidate seeking to unseat an incumbent claimed that the average family spends more than 30% of its annual income on housing. A housing expert was asked to investigate the claim. A random sample of 125
There are 604,474 bridges in the United States. A structural engineering team randomly sample 850 bridges and categorized each as either structurally deficient (restricted to light vehicles, require immediate rehabilitation to remain open, or are closed), functionally obsolete (load carrying
Robots are being used with increasing frequency on production lines to perform monotonous tasks. To determine whether a robot welder should replace human welders in producing automobiles, an experiment was performed. The time for the robot to complete a series of welds was found to be 38 seconds. A
According to FBI statistics, there were 342,000 robberies in the United States in 2009 (latest statistics available). A random sample of robberies was drawn and the amount of loss was recorded. Estimate with 95% confidence the total loss of all the robberies in the United States in 2009
Refer to Exercise 12.147. Also recorded was the weapon used (1 = firearm, 2 = knife or other cutting instrument, 3 = other, 4 = no weapon). Estimate with 90% confidence the number of crimes where a firearm was not used.
An important factor in attempting to predict the demand for new cars is the age of the cars already on the road. A random sample of 650 cars was drawn and the age of each car was recorded. Estimate with 99% confidence the age mean age of all American cars.
Refer to Exercise 12.149. A sample of 425 pickup trucks and SUVs was drawn and the age of the vehicles was recorded. Estimate with 95% confidence the mean age of trucks and SUVs.
Opinion Research International surveyed people whose household incomes exceed $50,000 and asked each for their top money-related new year’s resolutions. The responses are:1. Get out of credit card debt2. Retire before age 653. Die broke4. Make do with current finances5. Look for higher paying
In a large state university (with numerous campuses), the marks in an introductory statistics course are normally distributed with a mean of 68%. To determine the effect of requiring students to pass a calculus test (which at present is not a prerequisite), a random sample of 50 students who have
A random sample of complaints about American airlines was drawn and the type of complaint was recorded (1 = Flight problems (cancellations, delays, etc.), 2 = Customer service (unhelpful employees, inadequate means, or cabin service, treatment of delayed passengers), 3 = Baggage, 4 =
There are 138,592,000 workers in the United States. An economist took a random sample of 550 workers and recorded how they commuted to work (1 = drive alone, 2 = car pool, 3 = public transportation, 4 = walked, 5 = other, and 6 = worked at home). Is there enough evidence to infer that more than 75%
Refer to Exercise 12.154. Estimate with 95% confidence the number of workers who carpooled to work.
Refer to Exercise 12.154. Also recorded was the amount of time to commute to work on an average day. Estimate with 90% confidence the average commute time.
The routes of postal deliverers are carefully planned so that each deliverer works between 7 and 7.5 hours per shift. The planned routes assume an average walking speed of 2 miles per hour and no shortcuts across lawns. In an experiment to examine the amount of time deliverers actually spend
A national health care system was an issue in recent presidential election campaign and is likely to be a subject of debate for many years. The issue arose because of the large number of Americans who have no health insurance. Under the present system, free health care is available to poor people,
The manager of a branch of a major bank wants to improve service. She is thinking about giving $1 to any customer who waits in line for a period of time that is considered excessive. (The bank ultimately decided that more than 8 minutes is excessive.) However, to get a better idea about the level
Obesity is defined as having a Body Mass Index (BMI = 30 grams/kilogram2) over 30. A statistics practitioner took a random sample of American adults and classified their BMI as either 1. Under 20, 2. 20–30, 3. Over 30. There are 234,564,000 American adults. Estimate with 95% confidence the number
Engineers who are in charge of the production of springs used to make car seats are concerned about the variability in the length of the springs. The springs are designed to be 500 mm long. When the springs are too long, they will loosen and fall out. When they are too short, they will not fit into
Refer to Exercise 12.161. Suppose the engineers recoded the data so that springs that were the correct length were recorded as 1, springs that were too long were recorded as 2, and springs that were too short were recorded as 3. Can we infer at the 10% significance level that less than 90% of the
An advertisement for a major home appliance manufacturer claims that its repair personnel are the loneliest in the world because its appliances require the smallest number of service calls. To examine this claim, a researcher drew a random sample of 100 owners of 5-year-old washing machines. The
An oil company sends out monthly statements to its customers who purchased gasoline and other items using the company’s credit card. Until now, the company has not included a preaddressed envelope for returning payments. The average and the standard deviation of the number of days before payment
Exercise 12.165, suppose that the promoter decided to draw a sample of size 600 (because of financial considerations). Each teenager was asked whether he or she would attend the concert (2 = Yes, I will attend; 1 = No, I will not attend). Estimate with 95% confidence the number of teenagers who
The owner of a downtown parking lot suspects that the person he hired to run the lot is stealing some money. The receipts as provided by the employee indicate that the average number of cars parked in the lot is 125 per day and that, on average, each car is parked for 3.5 hours. To determine
Jim Cramer hosts CNBC’s “Mad Money” program. Mr. Cramer regularly makes suggestions about which stocks to buy and sell. How well has Mr. Cramer’s picks performed over the past two years (2005 to 2007)? To answer the question a random sample of Mr. Cramer’s picks was selected. The name of
Unfortunately, it is not uncommon for high school students in the United States to carry weapons (guns, knives, or clubs). To determine how prevalent this practice is a survey of high school students was undertaken. Students were asked whether they carried a weapon at least once in the previous 30
In 2006, the average household debt service ratio for homeowners was 14.35. The house-hold debt service ratio is the ratio of debt payments to disposable personal income. Debt payments consist of mortgage payments and payments on consumer debts. To determine whether this economic measure has
Refer to Exercise 12.170. Another measure of indebtedness is the financial obligations ratio, which adds automobile lease payments, rental on tenant occupied property, homeowners insurance, and property tax payments to the debt service ratio. In 2006, the ratio for homeowners was 17.62. Can we
Refer to Exercise 12.171. In 2006 the financial obligations ratio for renters was 25.97. Can we infer that financial obligations ratio for renters have increased between 2006 and this year 2009?
In 2010, there were 117,538,000 house-holds in the United States. There were 78,833,000 family households made up of married couples, single male, and single female households. To determine how many of each type a survey was undertaken. The results were stored using the codes 1 = married couple, 2
Wages and salaries make up only part of a total compensation. Other parts include paid leave, health insurance, and many others. In 2007, wages and salaries among manufacturers in the United States made up an average of 65.8% of total compensation. To determine if this changed in 2008 a random
Several decades ago a large proportion of Americans smoked cigarettes. However, in recent years many adults have quit. To measure the extent of current smoking a random sample of American adults was asked to report whether they smoked (1 = yes, 2 = no). There are 234,564,000 American adults.
Unfortunately, robbery is an all-too-frequent crime. Bank robberies tend to be the most lucrative for criminals. In most cases banks do not report the size of the loss. However, several researchers were able to gain access to bank robberies in England. Here are the variables recorded: Bank raid
How much money do winners go home with from the television quiz show Jeopardy? To determine an answer, a random sample of winners was drawn; the recorded amount of money each won is listed here. Estimate with 95% confidence the mean winnings for all the show’splayers.
A parking control officer is conducting an analysis of the amount of time left on parking meters. A quick survey of 15 cars that have just left their metered parking spaces produced the following times (in minutes). Estimate with 95% confidence the mean amount of time left for all the
Part of a university professor’s job is to publish his or her research. This task often entails reading a variety of journal articles to keep up to date. To help determine faculty standards, a dean of a business school surveyed a random sample of 12 professors across the country and asked
Most owners of digital cameras store their pictures on the camera. Some will eventually download these to a computer or print them using their own printers or a commercial printer. A file-processing company wanted to know how many pictures were stored on computers. A random sample of 10 digital
A growing concern for educators in the United States is the number of teenagers who have part-time jobs while they attend high school. It is generally believed that the amount of time teenagers’ spend working is deducted from the amount of time devoted to schoolwork. To investigate this problem,
Bankers and economists watch for signs that the economy is slowing. One statistic they monitor is consumer debt, particularly credit card debt. The Federal Reserve conducts surveys of consumer finances every 3 years. The last survey determined that 23.8% of American households have no credit cards
Generic drug sales make up about half of all prescriptions sold in the United States. The marketing manager for a pharmaceutical company wanted to acquire core information about the sales of generic prescription drugs. To do so, she randomly sampled 475 customers who recently filled prescriptions
During the last decade, many institutions dedicated to improving the quality of products and services in the United States have been forced. Many of these groups annually give awards to companies that produce high-quality goods and services. An investor believes that publicly traded companies that
Refer to Exercise 12.44. In addition to household debt, the survey asked each household to report the debt-to-income ratio. Estimate with 90% confidence the mean debt-to-income ratio.
Determine the sample size necessary to estimate a population proportion to within .03 with 90% confidence assuming you have no knowledge of the approximate value of the sample proportion.
Re-do Exercise 12.86 assuming that you know that the sample proportion will be no less than .75.
A statistics practitioner working for major league baseball wants to supply radio and television commentators with interesting statistics. He observed several hundred games and counted the number of times a runner on first base attempted to steal second base. He found there were 373 such events of
A dean of a business school wanted to know whether the graduates of her school used a statistical inference technique during their first year of employment after graduation. She surveyed 314 graduates and asked about the use of statistical techniques.After tallying up the responses, she found that
What type of educational background do CEOs have? In one survey, 344 CEOs of medium and large companies were asked whether they had an MBA degree. There were 97 MBAs. Estimate with 95% confidence the proportion of all CEOs of medium and large companies who have MBAs.
The GO transportation system of buses and commuter trains operates on the honor system. Train travelers are expected to buy their tickets before boarding the train. Only a small number of people will be checked on the train to see whether they bought a ticket. Suppose that a random sample of 400
Refer to Exercise 12.98. Assuming that there are 1 million travelers per year and the fare is $3.00 estimate with 95% confidence the amount of revenue lost each year. The following three exercises require the use of the Wilson Estimator.
Showing 8000 - 8100
of 88243
First
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
Last
Step by Step Answers
Get 50% OFF
Claim Now
.png){kind=small}
.png)
.png){kind=small}
.png){kind=small}
.png){kind=small}
