Questions and Answers of Statistics for Management

The production manager of a chemical plant wants to determine the roles that temperature and pressure play in the yield of a particular chemical produced at the plant. From past experience, she
The coach and the general manager of a team in the National Hockey League are trying to decide what kinds of players to draft. To help in making their decision, they need to know which variables are
The manager of a large hotel on the Riviera in southern France wanted to forecast the monthly vacancy rate (as a percentage) during the peak season. After considering a long list of potential
Should government improve standard of living of poor people? (1 = Government act; 2, 3, 4, 5 = People should help themselves.)The question of what should governments do and not do. For each question
There is no single definition of the middle class in the United States. For the purposes of analyzing the data from the Survey of Consumer Finances we have defined middle class on the basis of net
Each year the Internal Revenue Service of the United States issues a migration report that shows how many tax filers moved from one state to another. In an effort to answer the question of why so
Does income affect the way Americans choose which party to support? Conduct a statistical procedure to determine whether there are differences in income (RINCOME) between some or all of the eight
The survey asked the question, “Should government reduce income differences between rich and poor (EQWLTH: 1 = Government should reduce differences; 2, 3, 4, 5, 6, 7 = No government action)? Is
Is there enough statistical evidence to conclude that the eight political categories differ in their responses to this question, “Should government improve standard of living of poor people
The question that the survey asked is, “Should government do more or less to solve country’s problems (HELP NOT: 1 = Government should do more; 2, 3, 4, 5 = Government does too much)? Can we
With government-funded health insurance in the air the next question may be particularly relevant. Is it government’s responsibility to help pay for doctor and hospital bills HELPSICK: 1 =
What happens to Americans’ political philosophies as they grow richer? If they change we would expect differences in income (RINCOME) between the seven groups. Is there enough evidence to conclude
Is it government’s responsibility to help pay for doctor and hospital bills (HELPSICK: 1 = Government should help; 2, 3, 4, 5 = People should help themselves)?The four classes (CLASS: 1 = Lower
How does age and education affect income among middle-class households? To answer the question, conduct a regression analysis of the dependent variable INCOME using the independent variables AGE and
Summarize what you have discovered about the relationship between political philosophy and preference for government action in Exercises 16.146–16.149. In particular, discuss the coefficients of
To help make a decision about how to advertise for a particular product, a marketing manager hypothesized that the average American had completed high school (To complete high school, one needs to
The survey asked respondents to report the number of persons in the household who are related to the respondent and who earned any money from any job or employment (EARNRS).a. Estimate the mean
Last year 24 million Canadians made donations to charitable or nonprofit organizations. A random sample of donors was drawn and the amount of each respondent’s donation was recorded. Estimate with
In the United States as well as most other countries, the income tax is progressive in that richer people pay not only more in absolute terms but more in percentage as well. Other taxes are
It is a long-running joke that Britons have bad and missing teeth. However, Americans’ dental problems may be worse. In a study reported in the British Medical Journal a random sample of Americans
In the next 10 years, there will be the largest intergenerational wealth transfer in Canadian history, and the amount will likely grow over the next decade. There are 2.5 million Canadians 75 and
A tax preparation company compiled the taxable income of a random sample of waiters and waitresses. The taxable income was based on their pay stubs from the restaurant where each worked. a.
In another study on student loan indebtedness, a random sample of graduates 20–30 years old were asked the amount they paid monthly on their loans. Estimate with 99% confidence the mean monthly
Approximately 70% of students graduating from a 4-year program have student loan debt. To examine the problem, a random sample of graduates of 4-year colleges was taken and the amount of indebtedness
A survey of 25- to 35-year-old Americans with professional or Ph.D. degrees was asked to report their monthly incomes. Can we conclude at the 10% significance level that the mean income exceeds
Many Americans contributed to their 401k investment accounts. An economist wanted to determine how well these investments performed. A random sample of Americans with 401k investments were surveyed
A survey of American consumers asked respondents to report the amount of money they spend on bakery products in a typical month. If we assume that the population standard deviation is $5, can we
An economist surveyed homeowners in a large city to determine the percentage increase in their heating bills over the last 5 years. The economist particularly wanted to know if there was enough
Refer to Exercise 8.85. In order to improve the time spent by trucks waiting, both countries should improve the service rate by customs agents. Suppose that the governments decided that the
Refer to Exercise 7.70. Find the quartiles of the time to complete the research project.In exercise 7.70The demand for a daily newspaper at a newsstand at a busy intersection is known to be normally
Refer to Exercise 7.69. Find the probability of the following events.a. The launch of the new product takes more than 105 days.b. The launch of the new product takes more than 92 days.c. The launch
In a survey of consumer finances, it was determined that the average household debt is $250,000. If household debt is normally distributed with a standard deviation of $30,000 determine the quintiles.
The daily withdrawals from an ATM located at a service station is normally distributed with a mean of $50,000 and a standard deviation of $8,000. The operator of the ATM puts $64,000 in cash at the
A golfer playing a new course encounters a hole that requires a drive of 145 yards to successfully clear a pond. She knows that her drives are normally distributed with a mean of 155 yards and a
The mean monthly income of graduates of professional and Ph.D. degrees is $6,000 according to a recent PEW Research Center survey. If these incomes are normally distributed with a standard deviation
Refer to Exercise 8.54. Find the amount of sleep that is exceeded by only 25% of students.In exercise 8.54University and college students average 7.2 hours of sleep per night, with a standard
The Tesla Model S 85D is an electric car that the manufacturer claims can travel 270 miles on a single charge. However, the actual distance depends on a number of factors including speed and whether
Here is another function.f(x) = .2x 0 < x < 2 = .4 2 < x < 3.5a. Determine the probability that X is less than 2.b. Find the probability that X is less than 3.c.
Refer to Exercise 7.63.a. Determine the probability distribution of the total scores for both teams.b. Calculate the mean, variance, and standard deviation of the total scores for both teams.c.
Refer to Exercise 7.45. Compute the covariance and the coefficient of correlation.In exercise 7.45The following table lists the bivariate distribution of X and Y . х 2 .5 .1 .1 .3 2.
The following table lists the bivariate distribution of X and Y .a. Find the marginal probability distribution of X.b. Find the marginal probability distribution of Y.c. Compute the mean and variance
At a private golf course known for its excellent golfers a statistician quizzed the members to determine how many holes in one each made in their lifetime. From his work the following probability
Refer to Exercise 7.42. Compute the mean, variance, and standard deviation of the population.In exercise 7.42An expensive restaurant conducted an analysis of the number of people at tables from which
An expensive restaurant conducted an analysis of the number of people at tables from which the probability distribution was developed.If one table is selected at random determine the probability of
Determine whether each of the following is a valid probability distribution.a.b.c. 2 3 .1 .4 х .1 .3 P(x) 5 -6 0 P(x) .01 .01 .01 .97
Pew Research Center conducted a survey of countries around the world and asked respondents whether they were having a typical day, a good day, or a bad day. The results and the number of respondents
Refer to Exercise 6.86. The professor meets a student who has just graduated in less than five year. Determine the probability that he graduated with B.B.A. degree. In exercise 6.86A statistics
Refer to Exercise 6.85. An American under 40 tells you that he has student debt. What is the probability that he is managerial or professional? In exercise 6.85How many Americans under the age
Refer to Exercise 8.52. Find the probability of these events.a. A 2-year-old child is taller than 36 inches.b. A 2-year-old child is shorter than 34 inches.c. A 2-year-old child is between 30 and 33
Refer to Exercise 6.84.In exercise 6.84Refer to Exercise 6.83. Respondents in Greece, Hungary, and Poland were asked whether they approved or disapproved of the way the EU was dealing with the
Refer to Exercise 6.83.In exercise 6.83In June 2016, Britons were heading to the polls to vote in a referendum to decide whether the United Kingdom would leave the European Union. Pew Research Center
Refer to Exercise 6.76.In exercise 6.76Researchers at the University of Pennsylvania School Of Medicine have determined that children under 2 years old who sleep with the lights on have a 36% chance
Refer to Exercise 6.60.In exercise 6.60Determine all joint probabilities from the following.P(A) = .8P(Ac) = .2P(B\A) = .4P(B\Ac) = .7Find the following.a. P(A | B)b. P(AC | B)c. P(A | BC )d. P(AC |
Refer to Exercise 6.59.In exercise 6.59Given the following probabilities, compute all joint probabilities.P(A) = .9P(Ac) = .1P(B/A) = .4P(B/Ac)Determine P(A / B).
A statistics professor was in the process of comparing the pass rates (the percentage of entering students who graduate in 5 years or less) for B.A.€™s, B.B.A.€™s,
How many Americans under the age of 40 have student debts? A Pew Research Center attempted to answer the question by asking whether respondents had student debt and in what was their
After tabulating the results for NBC news the table of joint probabilities was created.a. Find the probability that one respondent selected at random would trust NBC News.b. What is the probability
Economists frequently make use of quintiles (i.e., the 20th, 40th, 60th, and 80th percentiles) particularly when discussing incomes. Suppose that in a large city household incomes are normally
Exercise 4.67 addressed the problem of setting an appropriate speed limit on highways. Automotive experts believe that the “correct” speed is the 85th percentile. Suppose that the speeds on a
According to a PEW Research Center survey, the mean student loan at graduation is $25,000. Suppose that student loans are normally distributed with a standard deviation of $5,000. A graduate with a
SAT scores are normally distributed with a mean of 1,000 and a standard deviation of 300. Find the quartiles.
Find the probabilities.1. P(Z < 1.60)2. P(Z < 1.61)3. P(Z < 1.65)4. P(Z < −1.39)5. P(Z < −1.80)6. P(Z < −2.16)7. P(−1.30 < Z < .70)8. P(Z > −1.24)9. P(Z <
The following density function describes the random variable X.f(x) = .40 − .10x 0 < x < 4 = .10x − .40 4 < x < 6a. What is the probability that X is less than 2?b. Find the
The following density function describes the random variable X.F(x) = .10 0 < x < 2 = .20 2 < x < 5 = .15 5 < x < 6 = .05 6 < x < 7a. Calculate the probability
Here is another density function.F(x) = .40 0 < x < 1 = .05 1 < x < 13a. Determine the probability that X is less than 8.b. What is the probability that X lies between .4 and 10?
A random variable is uniformly distributed between 100 and 150.a. Draw the density function.b. Find P(X > 110).c. Find P(120 < X < 135).d. Find P(X < 122).
Hikers and other outdoor enthusiasts have a new concern, the Zika virus. Physicians are recommending that people use a mosquito repellant while in areas where mosquitoes are present. A statistician
Americans are getting married (if at all) at a higher age than in the past. A marketing manager for a baby food maker wanted an estimate of how old are Americans when they have their first child
When the economy is healthy many firms ask their employees to put in overtime, which usually means working more than 40 hours per week. Is the average working American working for more than 40 hours
How well were American families doing in 2014? One very good guide is total family income (INCOME). Estimate the income for the average American family.
A large number of American families are invested in the stock market. Many have various pension plans that use contributed funds to buy stocks. Many others have directly held shares in the stock
In 2013, the housing market started picking up. Were people getting themselves too much into debt and hoping that the price of their homes would increase? One way to judge is to determine the size of
In the United States, there is no capital gains on houses until the last one is sold. Up to that point any gains are considered unrealized capital gains or losses on primary residence. Estimate the
According to the United Census the average expenditure for food away from home was $2625. Is there enough evidence to infer that the average middle-class households spends less (FOODAWAY)?
The interest rates charged by credit card companies is so high that consumers are advised to pay off their credit card debt as quickly as possible. To see if people are following this advice,
Suppose that you used the sample size calculated in Exercise 12.86 and found p^ = .5.a. Estimate the population proportion with 90% confidence.b. Is this the result you expected? Explain.
Refer to Exercise 12.105. If the number of professors between the ages of 55 and 64 is 75,000, estimate the total number of such professors who plan to retire early.
The proportion of Americans living in homes that they owned in 2010 was 65.8%. Is there sufficient evidence to infer that that figure increased by 2013? (HOUSECL: 1 = Owns)
In the 2010 census, 16.8% of American adults entered college but did not finish. Using the data from the Survey of Consumer Finances of 2013 test, determine whether that figure increased (EDCL: 3 =
The proportion of women who did not finish high school was 12.4% according to the census in 2010. Is there enough statistical evidence to conclude that the proportion has decreased in 2013 (HHSEX: 2
The 2010 census showed that the percentage of Black Americans who did not finish high school was 15.8%. Did this figure decrease by 2013? Conduct a test to determine whether there is enough evidence
The 2010 Census showed that the percentage of American adults who had an advanced degree (Read: graduate) was 10.5%. Is there sufficient evidence to infer that by 2013 that figure had been increased
Among Democratic and Republicans only is there enough evidence to infer that there are more Democrats than Republicans (PARTYID3: 1 = Democrat, 3 = Republican)? (Caution: Tricky question)
Among Liberals and Conservatives only is there enough evidence to infer that there are more Conservatives than Liberals (POLVIEWS3: 1 = Liberal, 3 = Conservative)?
Is there a contradiction between the results in Exercises 12.175 and 12.176? Explain.
The birth rate in many countries is falling. This will create problems in the future because there will be less people contributing taxes and more retired people receiving government pensions. The
If there was gender equality in the head of household designation the number of households with males head of households would equal the number of households with females as heads of households.
SCF2013:\All* How many American adults (18 and over) are working in some way? Estimate the number (LF: 1 = Working in some way).
Government debt and personal debt are a growing concern. Estimate the number of households that have debts (HDEBT: 1 = Yes).
Another sign of financial problems is when a household is late with at least one payment. Estimate with 90% confidence the number of households that had a least one late payment in the preceding 12
Another sign of financial difficulties is when a household finds that overall expenses are unusually high. Estimate with 99% confidence the number of households whose expenses are unusually high
Is a graduate degree a pathway to a wealthy household? Estimate the proportion of wealthy households whose heads have graduate degrees (EDUC: 17 = Graduate school).
How long does it take to become wealthy? One way to answer the question is to examine the age of the head of an average wealthy household.a. Conduct a test to determine whether there is enough
How does one get to be in this class whose minimum household net worth is about $9.5 million. Could this be achieved through high income alone? Examine this issue by estimating the mean annual income
Do wealthy households have late payments? Estimate the proportion of wealthy households that had at least one late payment in the previous year (LATE: 1).
Net worth is defined as the difference between total assets and total liabilities including debt. Does high net worth mean that these households have little or no debt?a. Answer the question by
Checking accounts are often used for household expenditures. Because they pay no interest, most households including wealthy ones keep a minimum amount in these accounts.a. Estimate the mean total
Is it true that an apple a day keeps the doctor away? A study designed and conducted by the National Health and Nutrition Examination Study (results published in the Journal of the American Medical
Michigan State’s Collegiate Employment Research Institute collected data from mid-August to mid-September, tapping the employment offices at 200 schools, which gathered tarting salary data
Does drinking hot chocolate boost the memory in older people? A random sample of people around the age of 73 was recruited. All had some form of cognitive deterioration. Half the participants drank

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