A study of the amount of rainfall and the quantity of air pollution removed produced the following data:(a) Find the equation of the regression line to predict, the particulate removed from the...
The demand for a product of Carolina Industries varies greatly from month to month. The probability distribution in the following table, based on the past two years of data, shows the companys...
The mean serves as the balance point for any distribution because the sum of all scores, expressed as positive and negative distances from the mean, always equals zero. (a) Show that the mean...
There is a 50-50 chance that the queen carries the gene of hemophilia. If she is a carrier, then each prince has a 50-50 chance of having hemophilia independently. If the queen is not a carrier, the...
Assume the length X in minutes of a particular type of telephone conversation is a random variable with probability density function(a) Determine the mean length JE(X) of this type of telephone...
Companies that do business over the Internet can often obtain probability information about Web site visitors from previous Web sites visited. For instance, the Q.M. in Action, Internet Marketing,...
A project was planned using PERT with three time estimates. The expected completion time of the project was determined to be 40 weeks. The variance of the critical path is 9. (a) What is the...
In a study of incentives used by companies to retain mature workers by The Conference Board, it was reported that 41% use flexible work arrangements. Suppose that of those companies that do not use...
Suppose a subdivision on the southwest side of Denver, Colorado, contains 1,500 houses. The subdivision was built in 1983.A sample of 100 houses is selected randomly and evaluated by an appraiser. If...
A machine used for lling plastic bottles with a soft drink has a known standard deviation of = 0.05 liter. The target mean ll volume is = 2.0 liters. (a) Describe the sampling distribution of x,...
A researcher wanted to see whether there is a significant difference in resting pulse rates for men and women. The data she collected are displayed in the box-plots and summarized in the next column....
A producer of computeraided design software for the aerospace industry receives numerous calls for technical support. Tracking software is used to monitor response and resolution times. In addition,...
The U.S. Department of Transportation maintains statistics for mishandled bags per 1,000 airline passengers. In the first nine months of 2009, airlines had mishandled 3.89 bags per 1,000 passengers....
The following cross tabulation shows the number of households (1000s) in each of the four regions of the United States and the number of households at each income level (U.S. Census bureau website,...
Which of the following are NLP problems, and why? (a) Maximize profit = 3X1 + 5X2 + 99X3 Subject to X1 10 X2 5 X3 18 (b) Maximize cost = 25X1 + 30X2 + 8X1 X2 Subject to X1 8 X1 + X2 12 0.0005X1 ...
Forbes magazine (www.Forbes.com) ranks NFL teams by value each year. The data below are the value of the Indianapolis Colts from 1998 to 2008. a. Construct a time series plot. What type of pattern...
The average cost per night of a hotel room in New York City is $273 (Smart Money, March 2009). Assume this estimate is based on a sample of 45 hotels and that the sample standard deviation is $65. a....
A data set on monthly expenditures (rounded to the nearest dollar) incurred on fast food by a sample of 500 households has a minimum value of $3 and a maximum value of $147. Suppose we want to group...
An automotive part must be machined to close tolerances to be acceptable to customers. Production specifications call for a maximum variance in the lengths of the parts of .0004. Suppose the sample...
A research hypothesis is that the variance of stopping distances of automobiles on wet pavement is substantially greater than the variance of stopping distances of automobiles on dry pavement. In the...
Porter Investments needs to develop an investment portfolio for Mrs. Singh from the following list of possible investments: Mrs. Singh has a total of $60,000 to invest. The following conditions must...
Suppose you have quarterly data on new housing starts, interest rates, and real per capita income. Specify a model for housing starts that accounts for possible trends and seasonality in the...
A proposed network of irrigation canals is described in the accompanying diagram. At peak demand, the flows at interchanges A, B, C, and D are as shown. (a) Find the possible flows. (b) If canal BC...
The article "Physical Properties of Cumin Seed" (J. of Agric. Engr. Res., 1996: 93-98) considered a quadratic regression of y 5 bulk density on x 5 moisture content. Data from a graph in the article...
Use Newtons method to find the coordinates of the inflection point of the curve y = e cos x, 0, < x < correct to six decimal places.
The Robotics Manufacturing Company operates an equipment repair business where emergency jobs arrive randomly at the rate of three jobs per 8-hour day. The companys repair facility is a...
The density of a plastic part used in a cellular telephone is required to be at least 0.70 g/cm3. The parts are supplied in large lots, and a variables sampling plan is to be used to sentence the...
Recall that in exercise 49, the admissions officer for Clearwater College developed the following estimated regression equation relating final college GPA to the student's SAT mathematics score and...
A study is to be conducted of the percentage of homeowners who own at least two television sets. How large a sample is required if we wish to be 99% confident that the error in estimating this...
In a study of police gunfire reports during a recent year, it was found that among 540 shots fired by New York City police, 182 hit their targets; and among 283 shots fired by Los Angeles police, 77...
Poindexter received a 55 on a biology test (X = 50) and a 45 on a philosophy test (X = 50). He is considering whether to ask his two professors to curve the grades using z-scores. (a) Does he want...
In each of the following experiments, identify the independent variable, the conditions of the independent variable, and the dependent variable: (a) Studying whether scores on a final exam are...
Jays Appliances sells micro-fridges according to the monthly demand distribution shown in the table at the top of the next page. Simulate 6 years of demand and compare theoretical and simulated...
The fraction of defective integrated circuits produced in a photolithography process is being studied. A random sample of 300 circuits is tested, revealing 13 defectives. Find a 95% two-sided CI on...
High blood pressure results from constriction of the arteries. To maintain a normal flow rate (flux), the heart has to pump harder, thus increasing the blood pressure. Use Poiseuilles Law to show...
From a survey of 250 coworkers you find that 155 would like the company to provide on-site day care. a) What is the value of the sample proportion p? b) What is the standard error of the sample...
In a particular year 40% of home sales were partially financed by the seller. A random sample of 250 sales is examined. a. The probability is 0.8 that the sample proportion is more than what amount?...
Mercury pollution is widely recognized as a serious ecological problem. Much of the mercury released into the environment originates as a byproduct of coal burning and other industrial processes. It...
A program to decrease littering was carried out in four cities in California's Central Valley starting in August 2011. The amount of litter in the streets (average pounds of litter collected per...
A normal population has known mean = 50 and variance 2 = 5. What is the approximate probability that the sample variance is greater than or equal to 7.44? less than or equal to 2.56? (a) For a random...
Drawing bolts from a lot of 20, containing one defective D, until D is drawn, one at a time and assuming sampling without replacement, that is, bolts drawn are not returned to the lot.
In item such as an increase in taxes, recall of elected officials, or an expansion of public services can be placed on the ballot if a required number of valid signatures are collected on the...
The accompanying table shows a portion of the average price for a gallon of gas for the 50 states during April 2012. The entire data set, labeled Gas_Prices_2012, can be found on the text website....
You are considering buying insurance for your new laptop computer, which you have recently bought for $1,500. The insurance premium for three years is $80. Over the three-year period there is an 8%...
The Nielsen ratings (percentage of U.S. households that tuned in) for the Masters golf tournament from 1997 through 2008 follow (Golf Magazine, January 2009): Year Rating 1997 ............ 11.2 1998...
The following table lists the probabilities of unemployed females and males and their educational attainment. a. If one unemployed person is selected at random, what is the probability that he or she...
The Snow Pea Restaurant is a Chinese carryout/delivery restaurant. Most of Snow Peas deliveries are within a 10-mile radius, but it occasionally delivers to customers more than 10 miles away. Snow...
One operation of a mill is to cut pieces of steel into parts that will later be used as the frame for front seats in an automobile. The steel is cut with a diamond saw and requires the resulting...
Let X1, X2, .. , X7 denote a random sample from a population having mean and variance. Consider the following estimators of μ: (a) Is either estimator unbiased? (b) Which estimator is best? In...
We arrived at Formula 6.3.2, V = ∫b 2πx f(x) dx, by using cylindrical shells, but now we can use integration by parts to prove it using the slicing method of Section 6.2, at least for the case...
Find the area of the region enclosed by the asteroid x = a cos3, y = a sin3. (Asteroids are explored in the Laboratory Project on page 659.)
A study by the Massachusetts Community & Banking Council found that blacks, and, to a lesser extent, Latinos, remain largely unable to borrow money at the same interest rate as whites (Boston Globe,...
Imagine that the investor in Exercise 37 invests $10,000 for one month in a company whose stock either goes up by 80% after a month with probability 1>2 or drops 60% with probability 1 > 2. After one...
This is your lucky day. You have just won a $20,000 prize. You are setting aside $8,000 for taxes and partying expenses, but you have decided to invest the other $12,000. Upon hearing this news, two...
A Retirement Condence Survey of 1153 workers and retirees in the United States 25 years of age and older conducted by Employee Benet Research Institute in January 2010 found that 496 had less than...
In a survey of 3029 adult Americans, the Harris Poll asked people whether they smoked cigarettes and whether they always wear a seat belt in a car. The table shows the results of the survey. For each...
The level of dissolved oxygen in the surface water of a lake is vital to maintaining the lake's ecosystem. Environmentalists from the University of Wisconsin monitored the dissolved oxygen levels...
Ten samples were taken from a plating bath used in an electronics manufacturing process, and the bath pH was determined. The sample pH values are 7.91, 7.85, 6.82, 8.01, 7.46, 6.95, 7.05, 7.35, 7.25,...
The following are four observations collected from each of three treatments. Test the hypothesis that the treatment means are equal. Use the .05 significance level. a. State the null and the...
The manager of a local fast-food restaurant is interested in improving the service provided to customers who use the restaurants drive-up window. As a first step in this process, the manager asks his...
Consider Ho: = 72 versus H1: > 72. A random sample of 16 observations taken from this population produced a sample mean of 75.2. The population is normally distributed with = 6. a. Calculate the...
Reconsider the loan application data in Table 7E.2. Set up the fraction nonconforming control chart for this process. Use the average sample size control limit approach. Plot the preliminary data in...
For the population in Example 2.2, consider the following sampling scheme: a. Find the probability of selection Ïi for each unit i. b. What is the sampling distribution of...
Wangs Concrete Service notes that the number of jobs each month follows the following distribution: 10 with probability 0.15, 11 with probability 0. 20, 12 with probability 0.20, 13 with probability...
In exercise 5, the owner of Showtime Movie Theaters, Inc., used multiple regression analysis to predict gross revenue (y) as a function of television advertising (x1) and newspaper advertising (x2)....
Assume that Google, Inc. hires employees on the different business days of the week (Monday through Friday) with equal likelihood. a.If two different employees are randomly selected, what is the...
Nationwide 13.7% of employed wage and salary workers are union members (down from 20.1% in 1983). A random sample of 300 local wage and salary workers showed that 50 belonged to a union. At = 0.05,...
In each of the following situations, summarize negative aspects of the sample design. a. A newspaper asks readers to vote at its Internet site to determine if they believe government expenditures...
a. Find the probability of getting exactly 7 girls in 8 births. b. Find the probability of getting 7 or more girls in 8 births. c. Which probability is relevant for determining whether 7 is a...
The following data represent the running times of films produced by 2 motion-picture companies. Test the hypothesis that the average running time of films produced by company 2 exceeds the average...
Many cardiac patients wear implanted pacemakers to control their heartbeat. A plastic connector module mounts on the top of the pacemaker. Assuming a standard deviation of 0.0015 and an approximate...
Lun Ho Stadium sells 2,200 tickets for a concert. It sells a quarter of them at a 20% discount and a further 10% at a 40% discount. How much must it charge for tickets if it wants to generate an...
The director of college admissions at a local university is trying to determine whether a students high school GPA or SAT score is a better predictor of the students subsequent college GPA. She...
A recent PwC Supply Global Chain survey indicated that companies that acknowledge the supply chain as a strategic asset achieve 70% higher performance (pwc. to/ VaFpGz). The Leaders in the survey...
Given a recent outbreak of illness caused by E. coli bacteria, the mayor in a large city is concerned that some of his restaurant inspectors are not consistent with their evaluations of a...
Perform one iteration of the steepest ascent method to locate the maximum of (x, y) = 4x + 2y + x2 2x4 + 2xy -3y2 Using initial guesses x = 0 and y = 0. Employ bisection to find the optimal step...
Soft tissue follows an exponential deformation behavior in uniaxial tension while it is in the physiologic a normal range of elongation. This can be expressed as Where = stress, = strain, and E o...
The owner of the Original Italian Pizza restaurant chain wants to understand which variable most strongly influences the sales of his specialty deep-dish pizza. He has gathered data on the monthly...
Using data from 2006 and with projections to 2021, total annual expenditures for national health care (in billions of dollars) can be described by E = 7.94x2 + 33.2x + 2190 where x is the number of...
The shelf life, in days, for bottles of a certain prescribed medicine is a random variable having the density function Find the probability that a bottle of this medicine will have a shell life of(a)...
The following data give the weekly amounts spent on groceries for a sample of 45 households. a. How many classes would you recommend? b. What class interval would you suggest? c. What would you...
Every now and then even a good diamond cutter has a problem and the diamond breaks. For one cutter, the rate of breaks is 0.1%. (a) What probability model seems well suited to this problem? Why? (b)...
How much time do Americans living in or near cities spend waiting in traffic, and how much does waiting in traffic cost them per year? The data in the file Congestion include this cost for 31 cities....
Estimate the common logarithm of 10 using-linear interpolation. (a) Interpolate between log 8 = 0.903900 and log 12 = 1.0791812. (b) Interpolate between log 9 = 0.9542425 and log 11 = 1.0413927. For...
Automobile magazines often compare models and rate them in various ways. One question that is often asked of car owners, would you buy the same model again? Suppose that a researcher for one magazine...
Octane is a measure of how much the fuel can be compressed before it spontaneously ignites. Some people believe that higher-octane fuels result in better gas mileage for their cars. To test this...
Listed below are the gross amounts (in millions of dollars) earned from box office receipts for the movie Harry Potter and the Half-Blood Prince. The movie opened on a Wednesday, and the amounts are...
The following contingency table shows opinion about global warming among U.S. adults, broken down by political party affiliation (based on a poll in October 2012 by Pew Research found at...
A consumer agency randomly selected 1700 flights for two major airlines, A and B. The following table gives the two-way classification of these flights based on airline and arrival time. less than 30...
According to an estimate, the average price of homes in Marthas Vineyard, Massachusetts, was $650,000 in 2011 (USA TODAY, August 11, 2011). A recent random sample of 70 homes from Marthas Vineyard...
Home values tend to increase over time under normal conditions, but the recession of 2008 and 2009 has reportedly caused the sales price of existing homes to fall nationwide (BusinessWeek, March 9,...
Refer to the Baseball 2012 data, which report information on the 30 Major League Baseball teams for the 2012 season. a. The mean attendance per team for the season was 2.495 million, with a standard...
In December 2001, 38% of adults with children under the age of 18 reported that their family ate dinner together 7 nights a week. In a recent poll, 403 of 1122 adults with children under the age of...
Consumer Reports tested 11 brands of vanilla yogurt and found these numbers of calories per serving: 130 160 150 120 120 110 170 160 110 130 90 a) Check the assumptions and conditions for inference....
A fast-food chain randomly attaches coupons for prizes to the packages used to serve french fries. Most of the coupons say Play again, but a few are winners. Seventy-five percent of the coupons pay...
A soft-drink bottler purchases nonreturnable glass bottles from a supplier. The lower specification on bursting strength in the bottles is 225 psi. The bottler wishes to use variables sampling to...
The file FISH.RAW contains 97 daily price and quantity observations on fish prices at the Fulton Fish Market in New York City. Use the variable log(avgprc) as the dependent variable. (i) Regress...
Use the tabular and graphical methods of descriptive statistics to learn how these variables contribute to the success of a motion picture. Include the following in your report. Tabular and graphical...
The automobile industry sold 657,000 vehicles in the United States during January 2009 (The Wall Street Journal, February 4, 2009). This volume was down 37% from January 2008 as economic conditions...
The file P08_18.xlsx categorizes 250 randomly selected consumers on the basis of their gender, their age, and their preference for our brand or a competitors brand of a low-calorie soft drink. Use a...