Question: A test was conducted for two overnight
A test was conducted for two overnight mail delivery services. Two samples of identical deliveries were set up so that both delivery services were notified of the need for a delivery at the same time. The hours required to make each delivery follow. Do the data shown suggest a difference in the median delivery times for the two services? Use a .05 level of significance for the test.
> A 2017 survey of sommeliers ranked the Finger Lakes region of New York state as the top wine region to visit (Thrillist web site). Finger Lakes vineyards typically specialize in growing grapes for white wines such as Chardonnay and Riesling. Seneca Hill
> The computer-gaming market in the United States is estimated at $18.5 billion as of 2017 (VentureBeat web site). Consider the case of Video Tech, a computer-gaming company located in San Jose, California. It is considering the production of one of two ne
> Myrtle Air Express decided to offer direct service from Cleveland to Myrtle Beach. Management must decide between a full price service using the company’s new fleet of jet aircraft and a discount service using smaller capacity commuter
> Investment advisors estimated the stock market returns for four market segments: computers, financial, manufacturing, and pharmaceuticals. Annual return projections vary depending on whether the general economic conditions are improving, stable, or decli
> A decision maker faced with four decision alternatives and four states of nature develops the following profit payoff table. The decision maker obtains information that enables the following probabilities assessments: P(s1) = .5, P(s2) = .2, P(s3) = .2
> The Gorman Manufacturing Company must decide whether to manufacture a component part at its Milan, Michigan, plant or purchase the component part from a supplier. The resulting profit is dependent upon the demand for the product. The following payoff tab
> To save on expenses, Rona and Jerry agreed to form a carpool for traveling to and from work. Rona preferred to use the somewhat longer but more consistent Queen City Avenue. Although Jerry preferred the quicker expressway, he agreed with Rona that they s
> In the following profit payoff table for a decision problem with two states of nature and three decision alternatives, the prior probabilities for s1 and s2 are P(s1) = .8 and P(s2) = .2. a. What is the optimal decision? b. Find the EVPI. c. Suppose th
> Consider the following hypothesis test. H0: µ ≥ 10 Ha: µ < 10 The sample size is 120 and the population standard deviation is 5. Use α = .05. If the actual population mean is 9, the probability of a Type II error is .2912. Suppose the researcher wants to
> Suppose that you are given a decision situation with three possible states of nature: s1, s2, and s3. The prior probabilities are P(s1) = .2, P(s2) = .5, and P(s3) = .3. With sample information I, P(I | s1) = .1, P(I | s2) = .05, and P(I | s3) = .2. Comp
> Lawson’s Department Store faces a buying decision for a seasonal product for which demand can be high, medium, or low. The purchaser for Lawson’s can order 1, 2, or 3 lots of the product before the season begins but ca
> Martin’s Service Station is considering entering the snowplowing business for the coming winter season. Martin can purchase either a snowplow blade attachment for the station’s pick-up truck or a new heavy-duty snowplo
> More than 500 scripted television series were available for viewing in 2018 (Hollywood Reporter website). New series typically start by producing a pilot episode that can be evaluated by a network before it agrees to pick up the series for production. Ha
> Dante Development Corporation is considering bidding on a contract for a new office building complex. Figure 19.9 shows the decision tree prepared by one of Dante’s analysts. At node 1, the company must decide whether to bid on the cont
> The following payoff table shows profit for a decision analysis problem with two decision alternatives and three states of nature. a. Construct a decision tree for this problem. b. Suppose that the decision maker obtains the probabilities P(s1) = .65,
> In a recent poll, six hundred adults were asked a series of questions about the state of the economy and their children’s future. One question was, “Do you expect your children to have a better life than you have had, a worse life, or a life about the sa
> A Pew Research Center survey asked adults if their ideal place to live would have a faster pace of life or a slower pace of life. A preliminary sample of 16 respondents showed 4 preferred a faster pace of life, 11 preferred a slower pace of life, and 1 s
> Are stock splits beneficial to stockholders? SNL Financial studied stock splits in the banking industry over an 18-month period. For a sample of 20 stock splits, 14 led to an increase in investment value, 4 led to a decrease in investment value, and 2 re
> The median annual income for families living in the United States is $56,200. Annual incomes in thousands of dollars for a sample of 50 families living in Chicago, Illinois, are shown. Use the sample data to see if it can be concluded that the families l
> Sparr Investments, Inc., specializes in tax-deferred investment opportunities for its clients. Recently Sparr offered a payroll deduction investment program for the employees of a particular company. Sparr estimates that the employees are currently avera
> In 2015 the median price of homes in Austin, Texas, was $248,640 (AustinHomeSearch website). A sample of 200 homes sold in the south Austin suburb of Westlake Hills found 111 homes with sales prices over $248,640 and 89 homes with sales prices under $248
> Net assets for the 50 largest stock mutual funds show a median of $15 billion. A sample of 10 of the 50 largest bond mutual funds follows. Using the median, can it be concluded that bond mutual funds are smaller and have fewer net assets than stock mu
> A student organization surveyed both current students and recent graduates to obtain information on the quality of teaching at a particular university. An analysis of the responses provided the following teaching-ability rankings. Do the rankings given b
> The rankings of a sample of professional golfers in both driving distance and putting are shown. What is the rank correlation between driving distance and putting for these golfers? Test for significance of the correlation coefficient at the .10 level of
> A national study by Harris Interactive, Inc., evaluated the top technology companies and their reputations. The following shows how 10 technology companies ranked in reputation and how the companies ranked in percentage of respondents who said they would
> The following data show the rankings of 11 states based on expenditure per student (ranked 1 highest to 11 lowest) and student–teacher ratio (ranked 1 lowest to 11 highest). a. What is the rank correlation between expenditure per stud
> Consider the following two sets of rankings for six items. Note that in the first case the rankings are identical, whereas in the second case the rankings are exactly opposite. What value should you expect for the Spearman rank-correlation coefficient
> Consider the following set of rankings for a sample of 10 elements. a. Compute the Spearman rank-correlation coefficient for the data. b. Use α = .05 and test for significant rank correlation. What is your conclusion?
> The better-selling candies are often high in calories. Assume that the following data show the calorie content from samples of M&€™s, Kit Kat, and Milky Way candies. Test for significant differences among the calorie content of these three
> A large corporation sends many of its first-level managers to an off-site supervisory skills training course. Four different management development centers offer this course. The director of human resources would like to know whether there is a differenc
> Refer to exercise 48. Assume the firm selects a sample of 50 surveys and repeat parts (b) and (c). What observation can you make about how increasing the sample size affects the probability of making a Type II error? Exercise 48: Fowle Marketing Researc
> The median number of part-time employees at fast-food restaurants in a particular city was known to be 18 last year. City officials think the use of part-time employees may be increasing. A sample of nine fast-food restaurants showed that seven restauran
> The National Football League (NFL) holds its annual draft of the nation’s best college football players in April each year. Prior to the draft, various sporting news services project the players who will be drafted along with the order
> Forty-minute workouts of one of the following activities three days a week will lead to a loss of weight, assuming no change in calories consumed. The following sample data show the number of calories burned during 40-minute workouts for three different
> Three admission test preparation programs are being evaluated. The scores obtained by a sample of 20 people who used the programs provided the following data. Use the Kruskal-Wallis test to determine whether there is a significant difference among the th
> A sample of 15 consumers provided the following product ratings for three different products. Five consumers were randomly assigned to test and rate each product. Use the Kruskal-Wallis test and α = .05 to determine whether there is a signi
> Chicago Midway International Airport and Baltimore/Washington International Thurgood Marshall Airport were the U.S. airports with the worst percentage of delayed flights in 2015 (Travel+Leisure website, https://www.travelandleisure.com/slideshows/best-an
> A certain brand of microwave oven was priced at 10 stores in Dallas and 13 stores in San Antonio. The data follow. Use a .05 level of significance and test whether prices for the microwave oven are the same in the two cities. Dallas …………………………….. San An
> Police records show the following numbers of daily crime reports for a sample of days during the winter months and a sample of days during the summer months. Use a .05 level of significance to determine whether there is a significant difference between t
> Each year Bloomberg Businessweek publishes statistics on the world’s 1000 largest companies. A company’s price/earnings (P/E) ratio is the company’s current stock price divided by the latest 12 months
> In 2018 a survey of 10,508 CEOs by PayScale. com, the range of annual salaries reported was from $73,187 to $336,550. But do CEO salaries differ across the two most populous states in the United States? Consider the salaries for CEOs who work for compani
> A production line operation is tested for filling weight accuracy using the following hypotheses. Hypothesis ………………………………… Conclusion and Action H0: µ = 16 …………………………….. Filling okay; keep running Ha: µ ≠ 16 …. Filling off standard; stop and adjust mach
> Sales personnel for Skillings Distributors submit weekly reports listing the customer contacts made during the week. A sample of 65 weekly reports showed a sample mean of 19.5 customer contacts per week. The sample standard deviation was 5.2. Provide 90%
> The gap between the earnings of men and women with equal education is narrowing but has not closed. Sample data for seven men and seven women with bachelor’s degrees are as follows. Data are shown in thousands of dollars. Men ……………………………….. Women 35.6 …
> Ten individuals participated in a taste test involving two brands of a product. Sample results show 7 preferred brand A, 2 preferred brand B, and 1 was unable to state a preference. With α = .05, test for a significant difference in the preferences for t
> Samples of starting annual salaries for individuals entering the public accounting and financial planning professions follow. Annual salaries are shown in thousands of dollars. a. Use a .05 level of significance and test the hypothesis that there is no d
> Two fuel additives are being tested to determine their effect on gasoline mileage. Seven cars were tested with additive 1 and nine cars were tested with additive 2. The following data show the miles per gallon obtained with the two additives. Use α = .05
> The Scholastic Aptitude Test (SAT) consists of three parts: critical reading, mathematics, and writing. Each part of the test is scored on a 200- to 800-point scale with a median of approximately 500. Scores for each part of the test can be assumed to be
> The Ladies Professional Golf Association (LPGA) ANA Inspiration tournament was held in April 2015 at the Mission Hills Country Club in Rancho Mirage, California. Shown here are first-round and second-round scores for a random sample of 13 golfers. Use &I
> Percents of on-time arrivals for flights in the past two years were collected for 11 randomly selected airports. Data for these airports follow. Use α = .05 to test the hypothesis that there is no difference between the median percent of on
> A sample of 10 men was used in a study to test the effects of a relaxant on the time required to fall asleep. Data for 10 subjects showing the number of minutes required to fall asleep with and without the relaxant follow. Use a .05 level of significance
> Two fuel additives are tested to determine their effect on miles per gallon for passenger cars. Test results for 12 cars follow; each car was tested with both fuel additives. Use α = .05 and the Wilcoxon signed-rank test to see whether ther
> Young Adult magazine states the following hypotheses about the mean age of its subscribers. H0: µ = 28 Ha: µ ≠ 28 a. What would it mean to make a Type II error in this situation? b. The population standard deviation is assumed known at σ = 6 years and th
> Competition in the personal computer market is intense. A sample of 450 purchases showed 202 Brand A computers, 175 Brand B computers, and 73 other computers. Use a .05 level of significance to test the null hypothesis that Brand A and Brand B have the s
> Nielsen Media Research identified The Big Bang Theory and This is Us as the two top-rated prime-time television series. In a local television preference survey, 750 individuals were asked to indicate their favorite prime-time television series: Three hun
> The following hypothesis test is to be conducted. H0: Median ≤ 150 Ha: Median > 150 A sample of 30 provided 22 observations greater than 150, 3 observations equal to 150, and 5 observations less than 150. Use α = .01. What is your conclusion?
> With the gasoline time series data from Table 17.1, show the exponential smoothing forecasts using α = .1. a. Applying the MSE measure of forecast accuracy, would you prefer a smoothing constant of α = .1 or α =
> Refer again to the gasoline sales time series data in Table 17.1. a. Using a weight of 1/2 for the most recent observation, 1/3 for the second most recent observation, and 1/6 for third most recent observation, compute a three-week weighted moving averag
> Refer to the gasoline sales time series data in Table 17.1. a. Compute four-week and five-week moving averages for the time series. b. Compute the MSE for the four-week and five-week moving average forecasts. c. What appears to be the best number of week
> Consider the following time series data. Construct a time series plot. What type of pattern exists in the data? a. Develop the three-week moving average forecasts for this time series. Compute MSE and a forecast for week 8. b. Use α = .2
> Consider the following time series data. a. Construct a time series plot. What type of pattern exists in the data? b. Develop the three-week moving average forecasts for this time series. Compute MSE and a forecast for week 7. c. Use α =
> Electric power consumption is measured in kilowatt-hours (kWh). The local utility company offers an interrupt program whereby commercial customers that participate receive favorable rates but must agree to cut back consumption if the utility requests the
> Consider the following time series data. a. Compute MSE using the most recent value as the forecast for the next period. What is the forecast for month 8? b. Compute MSE using the average of all the data available as the forecast for the next period. W
> A consumer research group is interested in testing an automobile manufacturer’s claim that a new economy model will travel at least 25 miles per gallon of gasoline (H0: µ ≥ 25). a. With a .02 level of significance and a sample of 30 cars, what is the rej
> Air pollution control specialists in southern California monitor the amount of ozone, carbon dioxide, and nitrogen dioxide in the air on an hourly basis. The hourly time series data exhibit seasonality, with the levels of pollutants showing patterns over
> Three years of monthly lawn-maintenance expenses ($) for a six-unit apartment house in southern Florida follow. a. Construct a time series plot. What type of pattern exists in the data? b. Identify the monthly seasonal indexes for the three years of la
> The quarterly sales data (number of copies sold) for a college textbook over the past three years follow. a. Construct a time series plot. What type of pattern exists in the data? b. Show the four-quarter and centered moving average values for this tim
> Refer to exercise 35. a. Deseasonalize the time series using the adjusted seasonal indexes computed in part (c) of exercise 35. b. Using statistical software, compute the linear trend regression equation for the deseasonalized data. c. Compute the deseas
> Consider the following time series data. a. Construct a time series plot. What type of pattern exists in the data? b. Show the four-quarter and centered moving average values for this time series. c. Compute seasonal indexes and adjusted seasonal index
> Three years of monthly lawn-maintenance expenses ($) for a six-unit apartment house in southern Florida follow. a. Construct a time series plot. What type of pattern exists in the data? b. Develop an estimated regression equation that can be used to ac
> Electric power consumption is measured in kilowatt-hours (kWh). The local utility company offers an interrupt program whereby commercial customers that participate receive favorable rates but must agree to cut back consumption if the utility requests the
> South Shore Construction builds permanent docks and seawalls along the southern shore of Long Island, New York. Although the firm has been in business only five years, revenue has increased from $308,000 in the first year of operation to $1,084,000 in th
> Air pollution control specialists in southern California monitor the amount of ozone, carbon dioxide, and nitrogen dioxide in the air on an hourly basis. The hourly time series data exhibit seasonality, with the levels of pollutants showing patterns that
> The quarterly sales data (number of copies sold) for a college textbook over the past three years follow. a. Construct a time series plot. What type of pattern exists in the data? b. Use the following dummy variables to develop an estimated regression
> Fowle Marketing Research, Inc., bases charges to a client on the assumption that telephone surveys can be completed within 15 minutes or less. If more time is required, a premium rate is charged. With a sample of 35 surveys, a population standard deviati
> Exercises 1 and 2 used different forecasting methods. Which method appears to provide the more accurate forecasts for the historical data? Explain. Exercise 2: Refer to the time series data in exercise 1. Using the average of all the historical data as
> Consider the following time series data. Whenever a categorical variable such as season has k levels, k 2 1 dummy variables are required. a. Construct a time series plot. What type of pattern exists in the data? b. Use the following dummy variables to
> Consider the following time series. a. Construct a time series plot. What type of pattern exists in the data? b. Use the following dummy variables to develop an estimated regression equation to account for seasonal effects in the data: Qtr1 = 1 if Quar
> The following data show Google revenue from 2008 (period 1) to 2017 (period 10) in billions of dollars (Alphabet, Inc. annual reports). These data are in the file GoogleRevenue. a. Construct a time-series plot. What type of pattern exists? b. Develop a
> Giovanni Food Products produces and sells frozen pizzas to public schools throughout the eastern United States. Using a very aggressive marketing strategy they have been able to increase their annual revenue by approximately $10 million over the past 10
> The following data show the number of Netflix subscribers worldwide for the years 2012 (period 1) to 2017 (period 6) (datawrapper website). The data are in the file NetflixSubscribers. a. Construct a time-series plot. What type of pattern exists in the
> The following data shows the average interest rate (%) for a 30-year fixed-rate mortgage over a ten-year period (FreddieMac website). Period ………………………………………………………………. Interest Rate (%) 1 …………………………………………………………………………………………. 6.41 2 ……………………………………………………………
> Skechers is a performance footwear company headquartered in Manhattan Beach, California. The sales for Skechers (in billions of dollars) for 2012 (period 1) to 2017 (period 6) are in the file SkechersSales (annualreports.com). a. Construct a time-series
> The Seneca Children’s Fund (SCF) is a local charity that runs a summer camp for disadvantaged children. The fund’s board of directors has been working very hard in recent years to decrease the amount of overhead expens
> The general fund revenue receipts for the state of Kentucky for 2003 (period 1) to 2017 (period 15) are in the file KYRevenue (ky.gov website). a. Construct a time-series plot. What type of pattern exists in the data? b. Develop a linear trend equation
> In 2017, ABC News reported that 58% of U.S. drivers admit to speeding. Suppose that a new satellite technology can instantly measure the speed of any vehicle on a U.S. road and determine whether the vehicle is speeding, and this satellite technology was
> Consider the following time series. a. Construct a time series plot. What type of pattern exists in the data? b. Using statistical software, develop the quadratic trend equation for the time series. c. What is the forecast for t = 8?
> Refer to the time series data in exercise 1. Using the average of all the historical data as a forecast for the next period, compute the following measures of forecast accuracy. a. Mean absolute error. b. Mean squared error. c. Mean absolute percentage e
> Consider the following time series. a. Construct a time series plot. What type of pattern exists in the data? b. Develop the linear trend equation for this time series. c. What is the forecast for t = 8?
> Consider the following time series data. a. Construct a time series plot. What type of pattern exists in the data? b. Develop the linear trend equation for this time series. c. What is the forecast for t = 8?
> Consider the following time series data. a. Construct a time series plot. What type of pattern exists in the data? b. Develop the linear trend equation for this time series. c. What is the forecast for t = 6?
> The U.S. Census Bureau tracks the median price for new home sales by month of year. The median prices for April for 22 years follow (U.S. Census Bureau website). a. Construct a time series plot. Comment on any pattern you observe. Discuss some of the f
> Ten weeks of data on the Commodity Futures Index are 7.35, 7.40, 7.55, 7.56, 7.60, 7.52, 7.52, 7.70, 7.62, and 7.55. a. Construct a time series plot. What type of pattern exists in the data? b. Compute the exponential smoothing forecasts for α = .2. c. C
> The following time series shows the sales of a particular product over the past 12 months. a. Construct a time series plot. What type of pattern exists in the data? b. Use α = .3 to compute the exponential smoothing forecasts for the time
> The values of Alabama building contracts (in $ millions) for a 12-month period follow. 240 350 230 260 280 320 220 310 240 310 240 230 a. Construct a time series plot. What type of pattern exists in the data? b. Compare the three-month moving average app
> Corporate triple-A bond interest rates for 12 consecutive months follow. 9.5 9.3 9.4 9.6 9.8 9.7 9.8 10.5 9.9 9.7 9.6 9.6 a. Construct a time series plot. What type of pattern exists in the data? b. Develop three-month and four-month moving averages for
> Internet users were recently asked online to rate their satisfaction with the web browser they use most frequently. Of 102,519 respondents, 65,120 indicated they were very satisfied with the web browser they use most frequently. a. What is the sample pro
> For the Hawkins Company, the monthly percentages of all shipments received on time over the past 12 months are 80, 82, 84, 83, 83, 84, 85, 84, 82, 83, 84, and 83. a. Construct a time series plot. What type of pattern exists in the data? b. Compare the th
> With a smoothing constant of α = .2, equation (17.2) shows that the forecast for week 13 of the gasoline sales data from Table 17.1 is given by F13 = .2Y12 + .8F12. However, the forecast for week 12 is given by F12 = .2Y11 + .8F11. Thus, we could combine
> Consider the following time series data. Using the naive method (most recent value) as the forecast for the next week, compute the following measures of forecast accuracy. a. Mean absolute error. b. Mean squared error. c. Mean absolute percentage error
