In a survey of 4013 U.S. adults, 722 say they have seen a ghost. Construct a 99% confidence interval for the population proportion. Interpret the results. If convenient, use technology to construct...
The sugar content of the syrup in canned peaches is normally distributed. A random sample of n = 10 cans yields a sample standard deviation of s = 4.8 milligrams. Find a 95% two-sided confidence...
A random sample of 25 bottles of buffered aspirin contain, on average, 325.05 mg of aspirin with a standard deviation of 0.5 mg. Find the 95% tolerance limits that will contain 90% of the aspirin...
The Davis family of Atlanta, Georgia, is planning its annual summer vacation. Three vacation locations along with criteria weights and location ratings follow. What is the recommended...
A candy company fills a 20-ounce package of Halloween candy with individually wrapped pieces of candy. The number of pieces of candy per package varies because the package is sold by weight. The...
A U.S. Navy recruiting center knows from past experience that the heights of its recruits have traditionally been normally distributed with mean 69 inches. The recruiting center wants to test the...
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 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...
Kruuk et al. (1989) used a stratified sample to estimate the number of otter (Lutra lutra) dens along the 1400-km coastline of Shetland, UK. The coastline was divided into 242 (237 that were not...
The following table summarizes investment outcomes and corresponding probabilities for a particular oil well" X = the outcome in $p(x) -$40,000 (no oil)................ .25 10,000 (some...
Use the data in GPA2.RAW for this exercise. (i) Using all 4,137 observations, estimate the equation colgpa = (0 + (0 hsperc + (2 sat + u and report the results in standard form. (ii) Reestimate the...
Determine the value of c that makes the function f(x, y) =cxy a joint probability density function over the range 0
The following data represent the number of different communication activities (e.g., cell phone, text messaging, e-mail, Internet, and so on) used by a random sample of teenagers over the past 24...
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...
Before installing a high-tech laser exhibit near the exit area, a museum of American technology found the average contribution by patrons was $2.75 per person. For a sample of 30 patrons following...
A control chart is used to control the fraction nonconforming for a plastic part manufactured in an injection molding process. Ten subgroups yield the data in Table 7E.9. (a) Set up a control chart...
In Problem 5, if P(s1) = 0.25, P(s2) = 0.50, and P(s3) = 0.25, find a recommended decision for each of the three decision makers. (For the same decision problem, different utilities can lead to...
Foster Drugs, Inc., handles a variety of health and beauty aid products. A particular hair conditioner product costs Foster Drugs $2.95 per unit. The annual holding cost rate is 20%. An...
Consider the following returns for two investments, A and B, over the past four years: a. Which investment provides the higher return? b. Which investment provides less risk? c. Given a risk-free...
Use the data set WAGE2.RAW for this exercise. (i) Use the variable KWW (the "knowledge of the world of work" test score) as a proxy for ability in place of IQ in Example 9.3. What is the estimated...
Count the number of cars that pass by an intersection during consecutive five-minute periods on a highway leading into a city. Would these data allow us to use the Law of Large Numbers eventually to...
Suppose that a product is shipped in lots of size N = 5,000. The receiving inspection procedure used is single sampling with n = 50 and c = 1. (a) Draw the type-A OC curve for the plan. (b) Draw the...
Use CRIME4.RAW for this exercise. (i) Reestimate the unobserved effects model for crime in Example 13.9 but use fixed effects rather than differencing. Are there any notable sign or magnitude changes...
In a random sample of 200 Phoenix residents who drive a domestic car, 165 reported wearing their seat belt regularly, while another sample of 250 Phoenix residents who drive a foreign car revealed...
Impurities in the batch of final product of a chemical process often reflect a serious problem. From considerable plant data gathered, it is known that the proportion Y of impurities in a batch has a...
A 2010 poll conducted by NBC asked respondents whowould win Super Bowl XLV in 2011. The responses by20,825 people are summarized in the following table. Team ......... Number of Votes Atlanta Falcons...
Sharp Outfits is trying to decide whether to ship some customer orders now via UPS or wait until after the threat of another UPS strike is over. If Sharp Outfits decides to ship the requested...
It is important for airlines to follow the published scheduled departure times of flights. Suppose that one airline that recently sampled the records of 246 flights originating in Orlando found that...
A study was conducted to compare the effect of four manganese rates ( from MnSO4) and four copper rates ( from CuSO4 5H2O) on the yield of soybeans. A large field was subdivided into 32 separate...
A recent MBA graduate, Dara, has gained control over custodial accounts that her parents had established. Currently, her money is invested in four funds but she has identified several other funds as...
The following tableau represents a specific simplex iteration. All variables are nonnegative. The tableau is not optimal for either a maximization or a minimization problem. Thus, when a non basic...
Assume that you are working with the results from Problems 11.29 and 11.30. a. What is the value of the test statistic for the interaction effect? b. What is the value of the test statistic for the...
The time between arrivals of customers at an automatic teller machine is an exponential random variable with a mean of 5 minutes. (a) What is the probability that more than three customers arrive in...
A company operates four machines three shifts each day. From production records, the following data on the number of breakdowns are collected: Test the hypothesis (using a = 0.05) that breakdowns are...
A quality control specialist has sampled 25 widgets from the production line. A widget can have minor or major defects. Of the 25 sampled widgets, 4 have minor defects and 2 have major defects. What...
Researchers wanted to explore self-esteem in adolescent boys and adolescent girls. They used a 5-point Likert-type self-esteem inventory; a 1 = strongly disagree and 5 = strongly agree. Their results...
Ms. Lisa Monnin is the budget director for Nexus Media Inc. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample...
Use the data in ELEM94_95 to answer this question. The findings can be compared with those in Table 4.1. The dependent variable lavgsal is the log of average teacher salary and bs is the ratio of...
Suppose that P (A|B) = 0.7, P (A) = 0.5, and P (B) = 0.2. Determine P (B|A).
A Monster.com poll of 3057 individuals asked: Whats the longest vacation you plan to take this summer? The following relative frequency distribution summarizes the results. ResponseRelative Frequency...
Consider the monthly rent (Rent) of a home in Ann Arbor, Michigan, as a function of the number of bedrooms (Beds), the number of bathrooms (Baths), and square footage (Sqft). a. Access the data...
For a random sample of 125 British entrepreneurs, the mean number of job changes was 1.91 and the sample standard deviation was 1.32. For an independent random sample of 86 British corporate...
Reconsider the model of Prob. 7.1-1. You are now to conduct sensitivity analysis by independently investigating each of the following six changes in the original model. For each change, use the...
The National Fire Protection Association reported that house fires in the United States result in $6.8 billion in losses annually (National Fire Protection Association, September 2015). Suppose a...
A missile leaves the ground with an initial velocity ? 0? forming an angle ? 0? with the vertical as shown in figure The maximum desired altitude is ?R where R is the radius of the earth. The laws of...
Refer to the computer solution of Problem 12 in Figure THE MANAGEMENT SCIENTIST SOLUTION FOR THE QUALITY AIR CONDITIONING PROBLEM a. Identify the range of optimality for each objective function...
Refer to the Buena School District bus data. Select the variable referring to the number of miles traveled last month, and then organize these data into a frequency distribution. a. What is a typical...
A new-car dealer is leasing various brand-new models for the monthly rates (in dollars) listed below. Estimate the true population variance (and standard deviation) in leasing rates with 90%...
Hits to a high-volume Web site are assumed to follow Poisson distribution with a mean of 10,000 per day. Approximate each of the following: (a) The probability of more than 20,000 hits in a day (b)...
A random sample of n = 9 structural elements is tested for compressive strength. We know that the true mean compressive strength = 5500 psi and the standard deviation is = 100 psi. Find the...
The Streeter-Phelps model can be used to compute the dissolved oxygen concentration in a river below a point discharge of sewage (Figure), o = o s? ? k d L o /k d + k s ? k a (e ?kat? ? e ? (kd +...
Which of the following are probability distributions? Why? (a) RANDOM VARIABLE X PROBABILITY 2 ................... 0.1 1 ................. 0.2 0 ................... 0.3 1 ................... 0.25 2...
The following histogram summarizes the salaries (in $1,000,000s) for the 30 highest-paid players in the National Basketball Association (NBA) for the 2012 season (www.nba.com, data retrieved March...
Based on a Saint Index survey, when 1000 adults were asked to identify the most unpopular projects for their hometown, 54% included Wal-Mart among their choices. Consider the probability that among...
For the accompanying screen display, a simple random sample of size n = 40 was obtained from the population of duration times (seconds) of eruptions of the old Faithful geyser. a. What is the number...
While playing a coin- tossing game in which you are to guess whether heads or tails will appear, you observe 30 heads in a string of 50 coin tosses. (a) Test the null hypothesis that this coin is...
Suppose that in Problem 9.16, the standard deviation is 0.012 gallon. a. Repeat (a) through (d) of Problem 9.16, assuming a standard deviation of 0.012 gallon. Data From Problem 9.16: A bottled water...
The speeds of 55 cars were measured by a radar device on a city street: a. Classify these data into a grouped frequency distribution by using class boundaries 1218, 1824, . . . , 4854. b. Find the...
Cycle time in manufacturing can be viewed as the total time it takes to complete a product from the beginning of the production process. The concept of cycle time varies according to the industry and...
Listed below are the lead concentrations (in mg/g) measured in different Ayurveda medicines. Ayurveda is a traditional medical system commonly used in India. The lead concentrations listed here are...
A manufacturer of pens has hired an advertising agency to develop an advertising campaign for the upcoming holiday season. To prepare for this project, the research director decides to initiate a...
An agricultural cooperative guarantees that the mean shelf life of a certain type of dried fruit is at least 400 days. (a) State the null and alternative hypotheses, and identify which represents the...
A large retailer receives shipments of batteries for consumer electronic products in packages of 50 batteries. The packages are held at a distribution center and are shipped to retail stores as...
Solve the following LP problem by using the graphical procedure and by using Excel: Maximize profit = 4X + 5y Subject to the constraints 5X + 2y < 40 3X + 6y < 30 X <7 2X y > 3 x,y >0
Professor Fair believes that extra time does not improve grades on exams. He randomly divided a group of 300 students into two groups and gave them all the same test. One group had exactly 1 hour in...
Assume a frequency curve for the following sets of data. What shape will the curve probably take? Use the following key: NO = normal NS = negatively skewed PS = positively skewed BI = bimodal RE =...
Using principles from physics it can be shown that when a cable is hung between two poles, it takes the shape of a curve y = f(x) that satisfies the differential equation where p is the linear...
Temperatures are measured at various points on a heated plate (Table P20.56). Estimate the temperature at (a) x = 4, y = 3.2, and (b) x = 4.3, y =2.7. x- 2 70.00 48. 15 35.03 27.07 25.00 60.00 90.00...
John Isaac Inc., a designer and installer of industrial signs, employs 60 people. The company recorded the type of the most recent visit to a doctor by each employee. A national assessment conducted...
203 students signed up for the Stats course in Exercise 39. They used the software suggested by the salesman, and scored an average of 108 points on the final with a standard deviation of 8.7 points....
Heller Manufacturing has two production facilities that manufacture baseball gloves. Production costs at the two facilities differ because of varying labor rates, local property taxes, type of...
A Pew Research study finds that 23% of Americans use only a cell phone, and no land line, for making phone calls (The Wall Street Journal, October 14, 2010). A year later, a researcher samples 200...
Suppose that a player draws a card at random from a pack of cards, and wins $15 if an Ace, king, Queen, or Jack is obtained, and otherwise wins the face value of the card in dollars. What is the...
The accompanying data file shows the midterm and final scores for 32 students in a statistics course. a. Estimate a student's final score as a function of his/ her midterm score. b. Find the standard...
John Daum and Chris Yin are star swimmers at a local college. They are preparing to compete at the NCAA Division II national championship meet, where they both have a good shot at earning a medal in...
The stepping-stone method is being used to solve a transportation problem. There is only one empty cell having a negative improvement index, and this index is 2. The stepping-stone path for this...
The following table contains the probability distribution for the number of traffic accidents daily in a small town: a. Compute the mean number of accidents per day. b. Compute the standard...
A researcher is evaluating customer satisfaction with the service and coverage of two phone carriers. Each individual in a sample of n = 25 uses one carrier for two weeks and then switches to the...
A company owns both a factory to produce its products and a retail outlet to sell them. A certain new product will be sold exclusively through this retail outlet. Its inventory of this product will...
Aurora Radiological Services is a health care clinic that provides radiological imaging services (such as MRIs, X-rays, and CAT scans) to patients. It is part of Front Range Medical Systems that...
Use the data in HPRICE1 .RAW to estimate the model Price = (0 + (1 sqrft + (2 bdrms + u, where price is the house price measured in thousands of dollars. (i) Write out the results in equation form....
A manufacturer of semiconductor devices takes a random sample of size n of chips and tests them, classifying each chip as defective or non-defective. Let Xi = 0 if the chip is non-defective and Xi =...
Multi bank is a large London bank with a branch office in Boston. The American government believes that a prominent American underworld figure, Mr. Z, has been depositing stolen money in both the...
Based on data from the Centers for Disease Control, the probability of a randomly selected person having gonorrhea is 0.00114. In tests for gonorrhea, blood samples from 16 people are combined. What...
A website that rents movies online recorded the age and the number of movies rented during the past month for some of their customers. Here are their data: Age Rentals 35 .... 9 40 .... 8 50 .... 4...
Students in a geography class are asked whether theyve visited Europe in the past 12 months and whether theyve flown on a plane in the past 12 months. a. For a randomly selected student, would you...
Vincenzo Baranello was diagnosed with high blood pressure. He was able to keep his blood pressure in control for several months by taking blood pressure medicine (amlodipine besylate). Baranellos...
The Security & Trust Bank employs 4 tellers to serve its customers. Customers arrive according to a Poisson process at a mean rate of 2 per minute. However, business is growing and management...
A paper in the Journal of the Association of Asphalt Paving Technologists (Vol. 59, 1990) describes an experiment to determine the effect of air voids on percentage retained strength of asphalt. For...
An article in the American Industrial Hygiene Association Journal (Vol. 37, 1976, pp. 418422) describes a field test for detecting the presence of arsenic in urine samples. The test has been proposed...
Let A be an event that a persons primary method of transportation to and from work is an automobile and B be an event that a persons primary method of transportation to and from work is a bus....
An article in The Wall Street Journal (July 11, 2008) outlined a number of reasons as to why the 16 teams in Major League Baseballs National League (NL) are inferior to the 14 teams in the American...
The port of South Louisiana, located 54 miles along the Mississippi River between New Orleans and Baton Rouge, is the largest bulk cargo port in the world. The U.S. Army Corps of Engineers reports...
A random sample of 50 university admissions officers was asked about expectations in application interviews. Of these sample members, 28 agreed that the interviewer usually expects the interviewee to...
Gven, Elaimis, Binokay, and Tan (2003) studied the distribution of paw preferences in rats using a computerized food-reaching test. For a sample of n = 144 rats, they found 104 right-handed animals....
Refer to the Cox Cable and Wire Company case. In the role of Meredith, design a spreadsheet with which to find a machine schedule and a corresponding inventory and shipment schedule that meets...
The owner of a restaurant that serves Continental style entres has the business objective of learning more about the patterns of patron demand during the Friday to Sunday weekend time period. Data...
The number of minutes that a flight from Phoenix to Tucson is early or late is a random variable whose probability density is given by Where negative values are indicative of the flights being early...
In a circuit with impressed voltage E having resistance R, inductance L, and capacitance C in parallel, the current i satisfies the differential equation Suppose C = 0.3 farads, R = 1.4 ohms, L = 1.7...
Transactions to a computer database are either new items or changes to previous items. The addition of an item can be completed less than 100 milliseconds 90% of the time, but only 20% of changes to...