A study was made to determine if the subject matter in a physics course is better understood when a lab constitutes part of the course. Students were randomly selected to participate in either a...
A company selling licenses for new e-commerce computer software advertises that firms using this software obtain, on average during the first year, a yield of 10% on their initial investments. A...
A mail-order catalog firm designed a factorial experiment to test the effect of the size of a magazine advertisement and the advertisement design on the number of catalog requests received (data in...
TN Communications provides cellular telephone services. The company is planning to expand into the Cincinnati area and is trying to determine the best location for its trans- mission tower. The tower...
Management Decision Systems (MDS) is a consulting company that specializes in the development of decision support systems. MDS has a four-person team working on a current project with a small company...
In the manufacture of electroluminescent lamps, several different layers of ink are deposited onto a plastic substrate. The thickness of these layers is critical if specifications regarding the final...
Golf Shafts, Inc. (GSI) produces graphite shafts for several manufacturers of golf clubs. Two GSI manufacturing facilities, one located in San Diego and the other in Tampa, have the capability to...
The Nielsen Home Technology Report provided information about home technology and its usage. The following data are the hours of personal computer usage during one week for a sample of 50 persons....
Out-of-state tuition and fees at the top graduate schools of business can be very expensive, but the starting salary and bonus paid to graduates from many of these schools can be substantial. The...
The normal daily high temperatures (in degrees Fahrenheit) in January for 10 selected cities are as follows. 50, 37, 29, 54, 30, 61, 47, 38, 34, 61 The normal monthly precipitation (in inches) for...
Poindexter finds that r = .40 between the variables of number of hours studied (X) and number of errors on a statistics test (Y). He also finds that r = + .36 between the variables of time spent...
Heart disease can be cured by wearing a magnetic bracelet on your wrist. Determine whether the stated causal connection is valid. If the causal connection appears to be valid, provide an explanation.
In a steam engine the pressure P and volume V of steam satisfy the equation PV1.4 = k , where is a constant. (This is true for adiabatic expansion, that is, expansion in which there is no heat...
There is a declining interest among teenagers to pursue a career in science and health care (US News and World Report, May 23, 2011). Thirty college-bound students in Portland, Oregon, are asked...
A survey of the business school graduates undertaken by a university placement office asked, among other questions, in which area each person was employed. The areas of employment included: 1....
The Central Intelligence Agency has specialists who analyze the frequencies of letters of the alphabet in an attempt to decipher intercepted messages that are sent as ciphered text. In standard...
Leonard works as a waiter in an upscale city restaurant. He makes a very good salary plus tips. His monthly income varies based upon the nights he works. His quarterly dividend checks and interest...
It is generally believed that a practical major such as business or engineering can really pay off for college graduates (CNNMoney.com, July 22, 2010). Other studies have shown that it is not just...
The following sample data reflect shipments received by a large firm from three different vendors. a. Specify the competing hypotheses to determine whether quality is associated with the source of...
A company has two assembly lines, each of which stalls an average of 2.4 times per week according to a Poisson distribution. Assume that the performances of these assembly lines are independent of...
A social psychologist wishes to test the assertion that our attitude toward other people tends to reflect our perception of their attitude toward us. A randomly selected member of each of 12 couples...
Nielsen Media Research, children (ages 211) spend an average of 21 hours 30 minutes watching television per week while teens (ages 1217) spend an average of 20 hours 40 minutes. Based on the sample...
The article Americans Drowsy on the Job and the Road (Associated Press, March 28, 2001) summarized data from the 2001 Sleep in America poll. Each individual in a sample of 1004 adults was asked...
At the end of 2008, the variance in the semiannual yields of overseas government bond was 2 = .70. A group of bond investors met at that time to discuss future trends in overseas bond yields. Some...
Vincent Cardoza is the owner and manager of a machine shop that does custom order work. This Wednesday afternoon, he has received calls from two customers who would like to place rush orders. One is...
NWAC Electronics manufactures four types of simple cables for a defense contractor. Each cable must go through four sequential operations: splicing, soldering, sleeving, and inspection. The following...
Michigan Motors Corporation (MMC) just introduced a new luxury touring sedan. As part of its promotional campaign, the marketing department decided to send personalized invitations to test-drive the...
Kenichi Kaneko is the manager of a production department which uses 400 boxes of rivets per year. To hold down his inventory level, Kenichi has been ordering only 50 boxes each time. However, the...
Consider the following hypotheses: H0: 12.6 HA: > 12.6 A sample of 25 observations yields a sample mean of 13.4. Assume that the sample is drawn from a normal population with a known population...
How difficult is it to expand the Great Threads model to accommodate another type of clothing? Answer by assuming that the company can also produce sweatshirts. The rental cost for sweatshirt...
Consider the Everglade cash flow problem discussed in this chapter. Suppose that extra cash is kept in an interest-bearing savings account. Assume that any cash left at the end of a year earns 3...
Use the 2010 GSS file (GSS10SSDS) to investigate the relationship between the respondents education (EDUC) and the education received by his or her father and mother (PAEDUC and MAEDUC,...
Refer to Data Set 25 "Fast Food" and use the drive through service times for Burger King lunches. Begin with a lower class limit of 70 seconds and use a class width of 40 seconds. Data Set 25...
A uniform distribution is defined over the interval from 2 to 5. a. What are the values for a and b? b. What is the mean of this uniform distribution? c. What is the standard deviation? d. Show that...
A statistics practitioner wants to test the following hypotheses with = 20 and n = 100: H0: = 100 H1: > 100 a. Using = .10 find the probability of a Type II error when = 102. b. Repeat part (a)...
The Wirehouse Lumber Company will soon begin logging eight groves of trees in the same general area. Therefore, it must develop a system of dirt roads that makes each grove accessible from every...
To raise money for a new rectory, the members of a church hold a raffle. A total of n tickets are sold (numbered 1 through n), out of which a total of fifty winners are to be drawn presumably at...
Data from the office for national Statistics show that the mean age at which men in great Britain get married is 30.8 years (the Guardian, February 15, 2013). A news reporter noted that this...
A computer scientist is investigating the usefulness of two different design languages in improving programming tasks. Twelve expert programmers, familiar with both languages, are asked to code a...
Sales for Fast Kat, a 16-foot catamaran sailboat, have averaged 250 boats per month over the last five years, with a standard deviation of 25 boats. Assuming that the demand is about the same as past...
A chemical processing plant has a network of pipes that are used to transfer liquid chemical products from one part of the plant to another. The following pipe network has pipe flow capacities in...
Recent crime reports indicate that 3.1 motor vehicle thefts occur each minute in the United States. Assume that the distribution of thefts per minute can be approximated by the Poisson probability...
A manufacturing company makes two products. Each product can be made on either of two machines. The time (in hours) required to make each product on each machine is listed in the file S13_33.xlsx....
A random sample of 51 fatal crashes in 2009 in which the driver had a positive blood alcohol concentration (BAC) from the National Highway Trafc Safety Administration results in a mean BAC of 0.167...
The author is a member of the board of directors of a nonprofit organization that held a fund-raising auction. He recorded the opening bids suggested by the auctioneer and the final winning bids for...
An important feature of tablets is battery life, the number of hours before the battery needs to be recharged. The file Tablets contains the battery life of 12 WiFi only and 7 3G/4G/ WiFi 9 through...
The average one-way airfare from Pittsburgh to Washington, D.C., is $236. A random sample of 20 one-way fares during a particular month had a mean of $210 with a standard deviation of $43. At =...
The pH in a reactor varies sinusoidally over the course of a day. Use least-squares regression to fit Eq. (19.11) to the following data. Use your fit to determine the mean, amplitude, and time of...
Show a separate graph of the constraint lines and the solutions that satisfy each of the following constraints: a. A 0.25 (A + B) b. B 0.10 (A + B) c. A 0.50 (A + B)
Explain how to determine the number of variables and constraints that would be in a transportation problem simply by knowing the number of sources and the number of destinations.
Consider a multinomial experiment with n = 250 and k = 4. The null hypothesis to be tested is H0: p1 = p2 = p3 = p4 = 0.25. The observed frequencies resulting from the experiment are a. Specify the...
According to results from the Spine Patient Outcomes Research Trial, or SPORT, surgery for a painful, common back condition resulted in significantly reduced back pain and better physical function...
Assume that r2 equals .50 for the relationship between height and weight for adults. Indicate whether the following statements are true or false. (a) Fifty percent of the variability in heights can...
Reconsider the California Manufacturing Co. example presented in Sec. 12.1. The mayor of San Diego now has contacted the companys president to try to persuade him to build a factory and perhaps a...
The researchers in Exercise 12 decide to test the hypothesis. The degrees of freedom formula gives 51.83 df. Test the null hypothesis at ( = 0.05. Is the alternative one or two-sided? In Exercise 12...
Suppose that a spherical droplet of liquid evaporates at a race that is proportional to its surface area. dV/dt = kA Where V = volume (mm 3 ), t = time (h), k = the evaporation rater (mm/hr), and A...
The manager of a nightclub near a local university recorded the ages of the last 100 guests in the following cumulative frequency distribution. Ages ....... Cumulative Frequency 18 up to 22 ..... 45...
According to an online survey by Harris Interactive for job site CareerBuilder.com, more than half of IT (information technology) workers say they have fallen asleep at work ( InformationWeek ,...
A random sample of size n = 50 is taken from a population with mean = - 9.5 and standard deviation =2. a. Calculate the expected value and the standard error for the sampling distribution of the...
You are the foreman of the Bar-S cattle ranch in Colorado. A neighboring ranch has calves for sale, and you are going to buy some to add to the Bar-S herd. How much should a healthy calf weigh? Let x...
For 100 births, P(exactly 56 girls) = 0.0390 and P(56 or more girls) = 0.136. Is 56 girls in 100 births a significantly high number of girls? Which probability is relevant to answering that question?
An electronic office product contains 5000 electronic components. Assume that the probability that each component operates without failure during the useful life of the product is 0.999, and assume...
The figure shows a semicircle with radius 1, horizontal diameter PQ, and tangent lines at P and Q. At what height above the diameter should the horizontal line be placed so as to minimize the shaded...
By definition, the inverse sine w = arc sin z is the relation such that sin w = z. The inverse cosine w arcos z is the relation such that cos w = z. The inverse tangent, increase cotangent, inverse...
A data set of 5 observations for Concession Sales per person ($) at a theater and Minutes before the movie begins results in the following estimated regression model: Sales = 4.3 + 0.265 Minutes. The...
Consider a birth-and-death process with just three attainable states (0, 1, and 2), for which the steady-state probabilities are P0, P1, and P2, respectively. The birth-and-death rates are summarized...
The fairness of the South African lottery was recently challenged by one of the country's political parties. The lottery publishes historical statis¬tics at its website...
The average number of field mice per acre in a 5-acre wheat field is estimated to be 12. Find the probability that fewer than 7 field mice are found (a) On a given acre; (b) On 2 of the next 3 acres...
Here are weekly instruction times for school children in different countries: 23.8 hours (Japan), 26.9 hours (China), 22.2 hours (U.S.), 24.6 hours (U.K.), 24.8 hours (France). What do these results...
Recall that the cigarette industry requires that models in cigarette ads must appear to be at least 25 years old. Also recall that a sample of 50 people is randomly selected at a shopping mall. Each...
The Auto Company of America (ACA) produces four types of cars: subcompact, compact, intermediate, and luxury. ACA also produces trucks and vans. Vendor capacities limit total production capacity to...
Three tanks fight a three-way duel. Tank A has probability 1/2 of destroying the tank at which it fires, tank B has probability 1/3 of destroying the tank at which it fires, and tank C has...
Annual growth rates for individual firms in the toy industry tend to fluctuate dramatically, depending on consumers tastes and current fads. Consider the following growth rates (in percent) for two...
The restaurant in a large commercial building provides coffee for the occupants in the building. The restaurateur has determined that the mean number of cups of coffee consumed in a day by all the...
A manufacturing company regularly consumes a special type of glue purchased from a foreign supplier. Because the supplier is foreign, the time gap between placing an order and receiving the shipment...
Previous studies have shown that urban bus drivers have an extremely stressful job, and a large proportion of drivers retire prematurely with disabilities due to occupational stress. These stresses...
The past records of a supermarket show that its customers spend an average of $95 per visit at this store. Recently the management of the store initiated a promotional campaign according to which...
During an annual heating season, the average gas bill for customers in a New England community heating their homes with gas was $457. Assuming a normal distribution and a standard deviation of $80:...
Suppose that, on the average, 1/3 of the graduating seniors at a certain college have two parents attend the graduation ceremony, another third of these seniors have one parent attend the ceremony,...
A psychiatrist wants to know whether the level of pathology (Y) in psychotic patients 6 months after treatment can be predicted with reasonable accuracy from knowledge of pretreatment symptom ratings...
Models of inventory systems frequently consider the relationships among a beginning inventory, a production quantity, a demand or sales, and an ending inventory . For a given production period j, let...
Consider the following cumulative relative frequency distribution. Class .......... Cumulative Relative Frequency 150 up to 200 ...... 0.10 200 up to 250 ...... 0.35 250 up to 300 ...... 0.70 300 up...
According to a study published in the New England Journal of Medicine, overweight people on low-carbohydrate and Mediterranean diets lost more weight and got greater cardiovascular benefits than...
Read each of the following statements. Assuming that statistical hypotheses are set up to test them, classify each as a one-tailed or a two-tailed test. a. Maritz Marketing Research reports that 42%...
Federal resources have been tentatively approved for the construction of an outpatient clinic. In order to design a facility that will handle patient load requirements and stay within a limited...
The December 2011 Consumer Reports study described in Exercise 19 also found that 12 of the 22 "red snapper" packages tested were a different kind of fish. a) Are the conditions for creating a...
Rich and Betsy Cuik started a small business. They manufacture a microwavable coffee-to-go cup called Cuik Cuppa Coffee. It contains spring water and ground coffee beans in a tea-bag-like pouch. Each...
The maintenance staff of a large office building regularly replaces fluorescent ceiling lights that have gone out. During a visit to a typical floor, the staff may have to replace several lights. The...
An economics student wishes to see if there is a relationship between the amount of state debt per capita and the amount of tax per capita at the state level. Based on the following data, can she or...
Semiconductor lasers used in optical storage products require higher power levels for write operations than for read operations. High-power-level operations lower the useful life of the laser. Lasers...
The table (supplied by San Diego Gas and Electric) gives the power consumption in megawatts in San Diego County from midnight to 6:00 A.M. on December 8, 1999. Use Simpsons Rule to estimate the...
The Steelcase Workplace Index studied the types of workrelated activities that Americans did while on vacation in the summer. Among other things, 40% read work-related material. Thirty-four percent...
The article Theaters Losing Out to Living Rooms (San Luis Obispo Tribune, June 17, 2005) states that movie attendance declined in 2005. The Associated Press found that 730 of 1000 randomly selected...
You are given the following payoff table (in units of thousands of dollars) for a decision analysis problem: (a) Which alternative should be chosen under the maximin payoff criterion? (b) Which...
North Manufacturing has a demand for 1,000 pumps each year. The cost of a pump is $50. It costs North Manufacturing $40 to place an order, and the carrying cost is 25% of the unit cost. If pumps are...
According to Salary Wizard, the average base salary for a brand manager in Houston, Texas, is $88,592 and the average base salary for a brand manager in Los Angeles, California, is $97,417 (Salary...
The probability histogram represents the number of rooms in rented housing units in 2009. (a) What is the probability that a randomly selected rental unit has ï¬ve rooms? (b) What is the...
1. All other things the same, a 90% confidence interval is shorter than a 95% confidence interval. 2. Ninety-five percent z-intervals have the form of a statistic plus or minus 3 standard errors of...
In reading psychological research, you encounter the following statements. Interpret each one. (a) The IQ scores were approximately normally distributed. (b) A bimodal distribution of physical...
When bonding teeth, ortho dontists must maintain a dry field. A new bonding adhesive (called "Smartbond") has been developed to eliminate the necessity of a dry field. However, there is concern that...