According to a recent survey, the average family spends about $229 on electronics (computers, cell phones, etc.) in back-to-college spending per student. Suppose back-to- college family spending on electronics is normally distributed with a standard deviation of $54. If a family of a returning college student is randomly selected, a) What is the probability that they spend less than $150 on back-to-college electronics? b) What is the probability that they spend more than $400 on back-to-college electronics? c) What is the probability that they spend between $120 and $185 on back-to-college electronics?
> According to a study by Decision Analyst, 21% of the people who have credit cards are very close to the total limit on the card(s). Suppose a random sample of 600 credit card users is taken. What is the probability that more than 150 credit card users ar
> If a population proportion is .28 and if the sample size is 140, 30% of the time the sample proportion will be less than what value if you are taking random samples?
> Suppose a population proportion is .40, and 80% of the time when you draw a random sample from this population you get a sample proportion of .35 or more. How large a sample were you taking?
> A population proportion is .58. Suppose a random sample of 660 items is sampled randomly from this population. a) What is the probability that the sample proportion is greater than .60? b) What is the probability that the sample proportion is between .55
> A given population proportion is .25. For the given value of n, what is the probability of getting each of the following sample proportions? a) n = 110 and ˆp ≤ .21 b) n = 33 and ˆp > .24 c) n = 59 and .24 ≤ ˆp < .27 d) n = 80 and ˆp < .30 e) n = 800 and
> According to Nielsen Media Research, the average number of hours of TV viewing by adults (18 and over) per week in the United States is 33 hours. Suppose the standard deviation is 7.9 hours and a random sample of 42 adults is taken. a) What is the probab
> Studies have shown that about half of all workers who change jobs cash out their 401(k) plans rather than leaving the money in the account to grow. The percentage is much higher for workers with small 401(k) balances. In fact, a87% of workers with 401(k)
> Suppose a subdivision on the southwest side of Denver, Colorado, contains 1500 houses. The subdivision was built in 1983. A sample of 100 houses is selected randomly and evaluated by an appraiser. If the mean appraised value of a house in this subdivisio
> Suppose the average checkout tab at a large supermarket is $65.12, with a standard deviation of $21.45. Twenty-three percent of the time when a random sample of 45 customer tabs is examined, the sample average should exceed what value?
> The Statistical Abstract of the United States published by the U.S. Census Bureau reports that the average annual consumption of fresh fruit per person is 99.9 pounds. The standard deviation of fresh fruit consumption is about 30 pounds. Suppose an analy
> Find the probability in each case. a) N = 1000, n = 60, μ = 60, and σ = 6; P(x̅< 76.5) =? b) N = 90, n = 36, μ = 108, and σ = 3.46; P(107 < x̅ < 107.7) =? c) N = 250, n = 100, μ = 35.6, and σ = 4.89; P(x̅ ≥ 36) =? d) N = 5000, n = 60, μ = 125, and σ = 13
> A random sample of size 81 is drawn from a population with a standard deviation of 12. If only 18% of the time a sample mean greater than 300 is obtained, what is the mean of the population?
> Suppose a random sample of size 36 is drawn from a population with a mean of 278. If 86% of the time the sample mean is less than 280, what is the population standard deviation?
> A population is normally distributed, with a mean of 23.45 and a standard deviation of 3.8. What is the probability of each of the following? a) Taking a sample of size 10 and obtaining a sample mean of 22 or more b) Taking a sample of size 4 and getting
> A population has a mean of 50 and a standard deviation of 10. If a random sample of 64 is taken, what is the probability that the sample mean is each of the following? a) Greater than 52 b) Less than 51 c) Less than 47 d) Between 48.5 and 52.4 e) Between
> Give an example of how quota sampling could be used to conduct sampling by a company test marketing a new personal computer.
> Give an example of how convenience sampling could be used in a study of Fortune 500 executives to measure corporate attitude toward paternity leave for employees.
> An increasing number of consumers believe they have to look out for themselves in the marketplace. According to a survey conducted by the Yankelovich Partners for USA WEEKEND magazine, 60% of all consumers have called an 800 or 900 telephone number for i
> Give an example of how judgment sampling could be used in a study to determine how district attorneys feel about attorneys advertising on television.
> Develop a frame for the population of each of the following research projects. a) Measuring the job satisfaction of all union employees in a company. c) Interviewing passengers of a major airline about its food service. d) Studying the quality-control pr
> According to the Internal Revenue Service, income tax returns one year averaged $1,332 in refunds for taxpayers. One explanation of this figure is that taxpayers would rather have the government keep back too much money during the year than to owe it mon
> According to CBS Money Watch, the average monthly household cellular phone bill is $100. Suppose monthly household cell phone bills are normally distributed with a standard deviation of $11.35. a) What is the probability that a randomly selected monthly
> Tompkins Associates reports that the mean clear height for a Class A warehouse in the United States is 22 feet. Suppose clear heights are normally distributed and that the standard deviation is 4 feet. A Class A warehouse in the United States is randomly
> Suppose the Minitab output shown here represents the analysis of the length of home-use cell phone calls in terms of minutes. Describe the distribution of cell phone call lengths and interpret the meaning of the probability statements. Cumulative Distrib
> A manufacturing company produces a metal rod. Use the Excel output shown here to describe the weight of the rod. Interpret the probability values in terms of the manufacturing process. Normal Distribution Mean = 227 mg Standard Deviation = 2.3 mg x Value
> Shown here is a Minitab output. Suppose the data represent the number of sales associates who are working in a department store on any given retail day. Describe the distribution including the mean and standard deviation. Interpret the shape of the distr
> Incoming phone calls generally are thought to be Poisson distributed. If an operator averages 2.2 phone calls every 30 seconds, what is the expected (average) amount of time between calls? What is the probability that a minute or more would elapse betwee
> Determine the probabilities for the following normal distribution problems. a) μ = 604, σ = 56.8, x ≤ 635 b) μ = 48, σ = 12, x < 20 c) μ = 111, σ = 33.8, 100 ≤ x < 150 d) μ = 264, σ = 10.9, 250 < x < 255 e) μ = 37, σ = 4.35, x > 35 f) μ = 156, σ = 11.4,
> The Wall Street Journal reported some interesting statistics on the job market. One statistic is that 40% of all workers say they would change jobs for “slightly higher pay.” In addition, 88% of companies say that there is a shortage of qualified job can
> In a recent year, the average daily circulation of the Wall Street Journal was 2,276,207. Suppose the standard deviation is 70,940. Assume the paper’s daily circulation is normally distributed. On what percentage of days would circulation pass 2,400,000?
> Supermarkets usually become busy at about 5 P.M. on weekdays because many workers stop by on the way home to shop. Suppose at that time arrivals at a supermarket’s express checkout station are Poisson distributed, with an average of .8 person/minute. If
> According to the ICAO, the average operating cost of an A320 jet airliner is $2,270 per hour. Suppose the operating costs of an A320 jet airliner are normally distributed with a standard deviation of $175 per hour. At what operating cost would only 20% o
> With the growing emphasis on technology and the changing business environment, many workers are discovering that training such as reeducation, skill development, and personal growth is of great assistance in the job marketplace. A recent Gallup survey fo
> Coastal businesses along the Gulf of Mexico from Texas to Florida worry about the threat of hurricanes during the season from June through October. Businesses become especially nervous when hurricanes enter the Gulf of Mexico. Suppose the arrival of hurr
> According to the Polk Company, a survey of households using the Internet when buying or leasing cars reported that 81% were seeking information about prices. In addition, 44% were seeking information about products offered. Suppose 75 randomly selected h
> The Federal Reserve System publishes data on family income based on its Survey of Consumer Finances. When the head of the household has a college degree, the mean before- tax family income is $85,200. Suppose that 60% of the before-tax family incomes whe
> According to figures released by the National Agricultural Statistics Service of the U.S. Department of Agriculture, the U.S. production of wheat over the past 20 years has been approximately uniformly distributed. Suppose the mean production over this p
> According to the U.S. Bureau of the Census, about 75% of commuters in the United States drive to work alone. Suppose 150 U.S. commuters are randomly sampled. a) What is the probability that fewer than 105 commuters drive to work alone? b) What is the pro
> The Conference Board published information on why companies expect to increase the number of part-time jobs and reduce full-time positions. Eighty-one percent of the companies said the reason was to get a flexible workforce. Suppose 200 companies that ex
> What is the first big change that American drivers made when gas prices significantly increased? According to an Access America survey, 30% said that it was cutting recreational driving. However, 27% said that it was consolidating or reducing errands. If
> According to the U.S. Department of Labor, the average American household spends $762 on personal care products and services per year. Suppose annual expenditures on P (410 ≤ x ≤ 825) = .636456 − .213849 = .422607personal care products and services per h
> Suppose the average speeds of passenger trains traveling from Newark, New Jersey, to Philadelphia, Pennsylvania, are normally distributed, with a mean average speed of 88 miles per hour and a standard deviation of 6.4 miles per hour. a) What is the proba
> Suppose inter arrival times at a hospital emergency room during a weekday are exponentially distributed, with an average inter arrival time of 9 minutes. If the arrivals are Poisson distributed, what would the average number of arrivals per hour be? What
> According to Bureau of Labor Statistics data, the average income for a worker in the metropolitan Boston area is $65,420. Suppose average income for a worker in the metropolitan Boston area is normally distributed with a standard deviation of $4,246. A m
> According to The Wirthlin Report, 24% of all workers say that their job is very stressful. If 60 workers are randomly selected, a) What is the probability that 17 or more say that their job is very stressful? b) What is the probability that more than 22
> The Zumper National Rent Report lists the average monthly apartment rent in various locations in the United States. According to the report, the average cost of renting a one-bedroom apartment in Houston is $1,082. Suppose that the standard deviation of
> A business convention holds its registration on Wednesday morning from 9:00 a.m. until 12:00 noon. Past history has shown that registrant arrivals follow a Poisson distribution at an average rate of 1.8 every 15 seconds. Fortunately, several facilities a
> The U.S. Bureau of Labor Statistics releases figures on the number of full-time wage and salary workers with flexible schedules. The numbers of full-time wage and salary workers in each age category are almost uniformly distributed by age, with ages rang
> According to the U.S. Department of Agriculture, Alabama egg farmers produce millions of eggs every year. Suppose egg production per year in Alabama is normally distributed, with a standard deviation of 83 million eggs. If during only 3% of the years Ala
> Shown here is a graph of a binomial distribution for n = 12. Study the graph and from the graph, estimate what you think is the mean of this distribution. Approximately what do you think is the value of p and why? 0.3 0.25 0.2 0.15 0.1 0.05 0 1 2 3 4
> Determine the mean, the variance, and the standard deviation of the following discrete distribution. x _____________ P(x) 1 …………………………. .238 2 …………………………. .290 3 …………………………. .177 4 …………………………. .158 5 …………………………. .137
> For the cash flows shown (in $1000 units), calculate the value of x that makes the present worth in year 0 equal to $300,000 at an interest rate of 10% per year. Year Cash Flow, $1000 0 1 2 3 4 5 6 40 x 40 40 x 40 40
> For the diagram shown below, the respective values of n to calculate the present worth in year 0 by the equation P0 = 100(P∕A,10%,n1)(P∕F,10%,n2) are: (a) n1 = 6, n2 = 1 (b) n1 = 5, n2 = 2 (c) n1 = 7, n2 = 1 (d) n1 = 7
> The winner of a multistate mega millions lottery jackpot worth $175 million was given the option of taking payments of $7 million per year for 25 years, beginning 1 year from now, or taking $109.355 million now. The interest rate that renders the two opt
> Consider the common moral that stealing is wrong. Hector is with a group of friends in a local supermarket. One of Hector’s buddies takes a high energy drink from a 6-pack on the shelf, opens it, drinks it, and returns the empty can to the package, with
> Chemical costs associated with a packed-bed flue gas incinerator for odor control have been decreasing uniformly for 5 years because of increases in efficiency. If the cost in year 1 was $100,000 and it decreased by $5,000 per year through year 5, the pr
> At i = 8% per year, the annual worth for years 1 through 6 of the cash flows shown is closest to: (a) $302 (b) $421 (c) $572 (d) $824 0 1 800 2 700 3 نما 600 4 500 5 400 6 Years 300
> The present worth of an increasing geometric gradient is $23,632. The interest rate is 6% per year and the rate of change series is 4% per year. If the cash flow in year 1 is $3,000, the year in which the gradient ends is: (a) 7 (b) 9 (c) 11 (d) 12
> Adams Manufacturing spent $30,000 on a new sterilization conveyor belt, which resulted in a cost savings of $4202 per year. The length of time it should take to recover the investment at 8% per year is closest to: (a) Less than 6 years (b) 7 years (c) 9
> For the cash flows shown, find the value of x that makes the equivalent annual worth in years 1 through 7 equal to $300 per year. Use an interest rate of 10% per year. Start the analysis at x = $300 and use Goal Seek to solve. Year 0 1 2 3 Cash Flow,
> Hansus Enterprises is a start-up small business specializing in software systems for machine based high-school student tutoring in science and math. Sheryl Hansus, the owner, has spoken with lenders to obtain a loan of $50,000 now (year 0), and the same
> The operating cost of a pulverized coal cyclone furnace is expected to be $80,000 per year. The steam produced will be needed for 6 years—now through year 5. Determine the equivalent annual worth, A, in years 1 through 5 of the operating costs at an inte
> A large water utility is planning to upgrade its SCADA system for controlling well pumps, booster pumps, and disinfection equipment so that everything can be centrally controlled. Phase I will reduce labor and travel costs by $28,000 per year. Phase II w
> Calculate the present worth of 10 uniform payments of $8000 that begin 1 year from now at an interest rate of 10% per year.
> An arithmetic gradient has cash flows of $1000 in year 4, $1200 in year 5, and amounts increasing by $200 per year through year 10. If you use the factor 200(P∕G,10%,n) to find PG in year 3, the value of n you have to use in the P∕G factor is: (a) 10 (b)
> The negative arithmetic gradient series in Problem 3.44 is missing the value in year 4. Solve for this value on a spreadsheet. In doing so, display both the full amount of the missing payment and the extra amount over the expected amount of $−1600.
> An engineer who believes in “save now; play later” wants to retire in 30 years with $2.0 million. At 8% per year interest, the amount the engineer will have to invest each year (starting in year 1) to reach the $2 million goal is closest to: (a) $17,660
> A chip manufacturing company wants to have $10 million available 5 years from now in order to build new warehouse and shipping facilities. If the company can invest money at 10% per year, the amount that it must deposit each year in years 1 through 5 to
> A single deposit of $25,000 was made by your grandparents on the day you were born 25 years ago. The balance in the account today if it grew at 10% per year is closest to: (a) $201,667 (b) $241,224 (c) $270,870 (d) $296,454
> The cost of updating an outdated production process is expected to be $81,000 four years from now. The equivalent present worth of the update at 6% per year interest is closest to: (a) $51,230 (b) $55,160 (c) $60,320 (d) $64,160
> The amount of money the Teachers Credit Union should be willing to loan a developer who will repay the loan in a lump sum amount of $840,000 two years from now at the bank’s interest rate of 10% per year is: (a) $694,180 (b) $99,170 (c) $1,106,400 (d)
> A manufacturer of prototyping equipment wants to have $3,000,000 available 10 years from now so that a new product line can be initiated. If the company plans to deposit money each year, starting 1 year from now, the equation that represents how much the
> Aero Serve, Inc. manufactures cleaning nozzles for reverse pulse jet dust collectors. The company spent $40,000 on a production control system that will increase profits by $11,096 per year for 5 years. The rate of return per year on the investment is cl
> Jowel Smithers and Sonda Richards merged all of their financial resources and opened a mobile phone sales and repair business in the upscale Domain Mall in Los Angeles 10 years ago with an initial investment of $2.5 million. As revenues increased signifi
> Maintenance costs for a regenerative thermal oxidizer increased according to an arithmetic gradient for 5 years. The cost in year 1 was $7000. If the interest rate is 10% per year and the present worth of the costs for a 5-year period was $28,800, the am
> Detrich Products is planning to upgrade an aging manufacturing operation 5 years from now at a cost of $100,000. If the company plans to deposit money into an account each year for 4 years beginning 2 years from now (first deposit is in year 2) to pay fo
> A uniform series of payments begins in year 4 and ends in year 11. If you use the P∕A factor with n = 8, the P value you get will be located in year: (a) 0 (b) 3 (c) 4 (d) 5
> If you borrow $24,000 now at an interest rate of 10% per year and promise to repay the loan with payments of $3695 per year starting 1 year from now, the number of payments that you will have to make is closest to: (a) 7 (b) 8 (c) 11 (d) 14
> You found a report stating that the equivalent annual worth of chemical costs associated with a water treatment process were $125,000 per year for a 5-year period. The report stated that the cost in year 1 was $190,000 and the cost decreased by a unifor
> Stefanie is a design engineer with an international railroad locomotive manufacturing company in the state of Illinois. Management wants to return some of the engineering design work to the United States rather than export all of it to India, where their
> At a return rate of 20% per year, the amount of money you must deposit for five consecutive years starting 3 years from now for the account to contain $50,000 fifteen years from now is closest to: (a) $1565 (b) $1759 (c) $1893 (d) $2093
> You plan to pay $38,000 cash for the new truck you want to buy 5 years from now. You are a very astute investor; all your money earns at 20% per year. If you have already saved $9500, the amount your rich aunt has to give you 2 years from now (as a gradu
> In order to establish a contingency fund to replace equipment after unexpected breakdowns, a manufacturer of thin-wall plastic bottles plans to deposit $100,000 now and $150,000 two years from now into an investment account. Assuming the account grows at
> For the cash flows shown, you have been asked to calculate the present worth (in year 0) using i = 10% per year. Which of the following solutions is not correct? (a) P = 200 + 200(P∕A,10%,3) + 300(P∕A,10%,3)(Pâ&
> Assume you borrow $10,000 today and promise to repay the loan in two payments, one in year 2 and the other in year 4, with the one in year 4 being only half as large as the one in year 2. At an interest rate of 10% per year, the size of the payment in ye
> The maker of a motion-sensing towel dispenser is considering adding new products to enhance offerings in the area of touchless technology. If the company does not expand its product line now, it will definitely do so in 2 years. Assume the interest rate
> The cost of tuition at a large public university was $390 per credit hour 5 years ago. The cost today (exactly 5 years later) is $585. The annual rate of increase is closest to: (a) 5% (b) 7% (c) 9% (d) 11%
> For the cash flows shown, find the future worth in (a) year 5, and (b) year 4. Assume an i of 10% per year. Year 2 sto Cash Flow, $ 0 0 3000 01 3 4 3000 3000 5 3000
> The SEWA (Southwestern Electricity and Water Authority) authorized construction projects totaling $1.07 million to improve desalinization plant efficiency and salinity-reduction technology for reject chemicals. Three bids from potential vendors were rece
> For the data in Problem 2.60, find the year that your retirement account first exceeds (a) $2 million, and (b) then $3 million. In setting up the spreadsheet you wish to know the amount that must be deposited each year. Data from problem 2.60 You are a
> Apple Computer wants to have $2.1 billion available 5 years from now in order to finance initial production of a device that applies IOT technology for home use. The company expects to set aside uniformly increasing amounts of money each year to meet its
> You expect to contribute to an investment fund for your retirement over the next 30 years with an annual deposit of a yet-to-be determined amount. Assume your goal is to have $2 million available when you stop the annual desposits and that the fund is ab
> A company that utilizes carbon fiber 3-D printing wants to have money available 2 years from now to add new equipment. The company currently has $650,000 in a capital account and it plans to deposit $200,000 now and another $200,000 one year from now. Th
> In order to finance a new project costing $30 million, a company borrowed $21 million at 16% per year interest and used retained earnings valued at 12% per year for the remainder of the financing. The company’s weighted average cost of capital for the pr
> Identify at least five areas of personal finances in which engineering economic analysis can be used by you in the future. Answer: Examples are: house purchase; car purchase, credit card (which ones to use); personal loans (and their rate of interest
> The simple interest rate per year that will accumulate the same amount of money in 2 years as a compound interest rate of 20% per year is closest to: (a) 20.5% (b) 21% (c) 22% (d ) 23%
> The compound interest rate per year that amounts of $1000 one year ago and $1345.60 one year hence are equivalent to is closest to: (a) 8.5% per year (b) 10.8% per year (c) 20.2% per year (d) None of the above
> At a compound interest rate of 10% per year, the amount that $10,000 one year ago is equivalent to now is closest to: (a) $8264 (b) $9091 (c) $11,000 (d) $12,100
> The time it would take for money to double at a simple interest rate of 5% per year is closest to: (a) 10 years (b) 12 years (c) 15 years (d) 20 years
> All of the following mean the same as Minimum Attractive Rate of Return except: (a) Hurdle rate (b) Inflation rate (c) Benchmark rate (d) Cutoff rate
