New Semester
Started
Get
50% OFF
Study Help!
--h --m --s
Claim Now
Question Answers
Textbooks
Find textbooks, questions and answers
Oops, something went wrong!
Change your search query and then try again
S
Books
FREE
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Tutors
Online Tutors
Find a Tutor
Hire a Tutor
Become a Tutor
AI Tutor
AI Study Planner
NEW
Sell Books
Search
Search
Sign In
Register
study help
business
business statistics in practice
Business Statistics Plus Pearson Mylab Statistics With Pearson Etext 3rd Edition Norean R Sharpe ,Richard D De Veaux ,Paul Velleman - Solutions
=+Did the overall quality measure provided for these properties reflect these differences?
=+In Section 16.7 we saw data on commercial properties in a large U.S. city. One variable available for those properties is a “quality” ranking into one of 6 categories, with 1 as the “best” and 6 as the “worst.” A realtor wanted to know how that quality index related to the
=+6. As in Exercise 5, a process to make fishing strings produces spools with a desired mean length of 91.4 m (100 yds). The historical standard deviation is 1 cm (0.01 m). If samples of size 6 are taken and measured,
=+c) If the sample size were increased to 12, how would the answers to parts a and b change?
=+a) What is the center line for the R chart?
=+b) How long or short would the sample mean length would have to be to fall outside the 3s limit?
=+b) What is the standard deviation of the sample range?
=+a) What is the standard deviation of the sample mean?
=+5. A process to make fishing strings produces spools with a mean length of 91.4 m (100 yds). The historical standard deviation is 1 cm (0.01 m). If a sample size of 6 are taken and measured.
=+4. For the data in Exercise 1, suppose the historical standard deviation had been 0.1°C instead of 0.2°C. How would that change your answers to the questions in Exercise 3?Section 21.3
=+c) How large (or small) would the sample range have to be to fall outside the 3s limit?Section 21.5
=+g) Are any fourteen points in a row alternatively increasing and decreasing?h) Based on your answers to parts b–g, what do you conclude?
=+f) Are any six points in a row increasing (or decreasing)?
=+7. One of the ways in which the dental floss discussed in Exercise 5 can fail is if it snaps when pulled with a certain tension. Historically, only 2% of the tested floss snaps. Suppose boxes of size 50 are selected at random to be tested.a) What is the standard deviation for the sample
=+e) Are there eight points in a row on the same side of the mean?
=+d) Are four out of five consecutive points outside of 1s on either side?
=+c) Are two of three consecutive points outside of 2s on either side?
=+3. For the data in Exercise 1, instead of the specification limits,a) Use the historical standard deviation to set up 1, 2, and 3s limits and draw the control chart.b) Are any points outside the 3s limits on either side?
=+b) What might you recommend to the engineers given this value of Cp?Exercises Container #Temperature Loss 1°C2 Container #Temperature Loss 1°C2 1 3.89 7 4.22 2 3.71 8 4.02 3 4.14 9 4.48 4 4.12 10 3.93 5 3.74 11 3.87 6 3.99 12 3.94 M21_SHAR8696_03_SE_C21.indd 799 14/07/14 7:36 AM 800 CHAPTER 21
=+2. A computer screen manufacturing process must produce screens of uniform size. In particular, for a new tablet, the screen should be 10.1 inches long. The engineers have set 10.16 and 10.04 as the upper and lower specifications on screen length. If the actual process standard deviation is 0.01
=+b) What are the upper and lower 3s control limits?
=+a) Make a control chart of these data using the specification limits given.b) Does the process seem to be in control?c) What is the value of Cp for the process?d) Given this value of Cp, what recommendations might you make to the quality control team?
=+1. A producer of beverage containers wants to ensure that a liquid at 90°C will lose no more than 4°C after 30 minutes. Containers are selected at random and subjected to testing. Historical data shows the standard deviation to be 0.2°C. The quality control team has set 3.5 and 4.5°C as the
=+Organize these possible factors into a fishbone (Ishikawa) diagram to help them design experiments using these factors.
=+c) How many packages in a box of 50 would have to fail for a process to be declared out of control using the 3s control limits?
=+Using X and R charts with the desired mean of 18.15 oz. and the desired standard deviation of 0.08 oz., does the process seem to be in control now? If not, when did the process seem to slip out of control?
=+parameter values, construct a runs chart for the following weights of recent batches and comment on whether the process is in control. 18.03 18.00 18.12 17.81 18.23 18.11 18.23 18.19 18.00 18.05 18.12 18.05 18.14 18.16 18.11 18.19 18.26 18.11 18.15 18.07 18.04 18.14 18.00 18.21 18.12
=+After the report in the example on page 776, the candy company makes some changes to the pouring process and thinks that the mean is now 18.15 oz. and the standard deviation is 0.08 oz. Using these
=+Perform a process capability analysis on the fudge shop and comment on your findings
=+ Do you see any potential problems with the analysis?
=+What conclusions about the additive and car types do you draw?
=+A plot of the residuals vs. predicted values showed:2.5 0–2.5–5.0 Residuals (mpg)12.5 25.0 37.5 50.0 Predicted Values (mpg)
=+Square F-ratio P-value Type 2 23175.4 11587.7 2712.2 60.0001 Additive 1 92.1568 92.1568 21.57 60.0001 Interaction 2 51.8976 25.9488 6.0736 0.0042 Error 54 230.711 4.27242 Total 59 23550.2 M20_SHAR8696_03_SE_C20.indd 768 14/07/14 7:37 AM Exercises 769
=+A two-way ANOVA with interaction model was run, and the following ANOVA table resulted.Source DF Sum of Squares Mean
=+48. Gas additives. An experiment to test a new gasoline additive, Gasplus, was performed on three different cars: a sports car, a minivan, and a hybrid. Each car was tested with both Gasplus and regular gas on 10 different occasions, and their gas mileage was recorded. Here are the boxplots.50.0
=+c) If so, perform the hypothesis tests and state your conclusion. Be sure to state it in terms of head injury severity, seats, and vehicle types.
=+a) State the null hypotheses about the main effects (in words, not symbols).
=+A scatterplot of residuals vs. predicted values shows:0.6 0.3–0.3 0Residuals (severity index)2.8 2.9 3.0 3.1 Predicted Values (severity index)The ANOVA table follows:Source DF Sum of Squares Mean Square F-ratio P-value Seat 1 0.88713 0.88713 25.501 60.0001 Size 5 1.49253 0.29851 8.581 60.0001
=+Seat Effect (severity index)Driver Passenger Seat 2.7 2.4 3.0 3.3 Size Effect (severity index)Compact Light Medium Mini Pickup Van Size An interaction plot shows:2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 Compact Light Medium Mini Pickup Van Size Head Injury (severity index)Driver Passenger
=+47. Automotive safety. The National Highway Transportation Safety Administration runs crash tests in which stock automobiles are crashed into a wall at 35 mph with dummies in both the passenger and the driver’s seats. The THOR Alpha crash dummy is capable of recording 134 channels of data on
=+e) To check for significant differences between the shelf means, we can use a Bonferroni test, whose results are shown here. For each pair of shelves, the difference is shown along with its standard error and significance level. What does it say about the questions in part
=+d) Can we conclude that cereals on shelf 2 have a lower mean protein content than cereals on shelf 3? Can we conclude that cereals on shelf 2 have a lower mean protein content than cereals on shelf 1? What can we conclude?
=+c) What does the ANOVA table say about the null hypothesis? (Be sure to report this in terms of protein content and shelf placement.)
=+8. Rather than use the proportion of packages that contain defective floss, another quality control inspector simply counts the number of packages. If historically, only 1 package out of 50 is defective,
=+46. Cereal shelf placement, part 2. We also have data on the protein content on the 77 cereals in Exercise 45. Does protein content vary by shelf? Here’s a boxplot and an ANOVA table.6 54 32 1Protein (g)1 2 3 Shelf Source DF Sum of Squares Mean Square F-ratio P-value Shelf 2 12.4258 6.2129
=+e) To check for significant differences between the shelf means, we can use a Bonferroni test, whose results are shown at the top of the next column. For each pair of shelves, the difference is shown along with its standard error and significance level. What does it say about the questions in
=+d) Can we conclude that cereals on shelf 2 have a different mean sugar content than cereals on shelf 3? Can we conclude that cereals on shelf 2 have a different mean sugar content than cereals on shelf 1? What can we conclude?
=+c) What does the ANOVA table say about the null hypothesis? (Be sure to report this in terms of sugar content and shelf placement.)
=+b) What are the null and alternative hypotheses?
=+a) What kind of design or study is this?
=+45. Cereal shelf placement. Supermarkets often place similar types of cereal on the same supermarket shelf. The shelf placement for 77 cereals was recorded as well their sugar content. Does sugar content vary by shelf? Here’s a boxplot and an ANOVA table.15 10 50 1 2 3 Shelf Sugars (g)Source
=+c) The P-value of this F-statistic turns out to be 0.00000949. What does this say about the null hypothesis of equal means?
=+42. Process improvements. One way to improve a process is to eliminate non–value-added activities (e.g., extra movements) and wasted effort (e.g., looking for materials). A consultant was hired to improve the efficiency in a large shop floor operation. She tested three different workspace
=+d) Based on the two-way ANOVA results, management concluded that shift has a significant impact on the length of the part and that consequently operator inexperience is the root cause of the part problems. Do you agree with this conclusion? Explain.
=+Each scrubber was tested 5 times. For each run, the same material was produced, and the particulate emissions coming out of the scrubber were measured (in parts per billion). A partially complete Analysis of Variance table of the data is shown here.Source Sum of Squares DF Mean Square F-ratio
=+44. Smokestack scrubbers. Particulate matter is a serious form of air pollution often arising from industrial production. One way to reduce the pollution is to put a filter, or scrubber, at the end of the smokestack to trap the particulates. An experiment to determine which smokestack scrubber
=+f) What is the average size of the error standard deviation?
=+e) What would you like to see to justify the conclusions of the F-test?
=+d) What assumptions have you made to answer part c?
=+c) The P-value of this F-statistic turns out to be 0.075.What does this say about the null hypothesis of equal means?
=+b) Form the F-statistic by dividing the two mean squares.
=+a) Calculate the mean square of the treatments and the mean square of the error.
=+43. Tax return forms. In order to improve the format of tax return forms, a government agency developed two new forms. To determine which, if any, are superior to the current form, 30 individuals were asked to participate in an experiment. Each of the two new forms and the current one were
=+a) What is the standard deviation of the number of defective packages?
=+d) Based on the two-way ANOVA results, management concludes that neither the workspace design nor the storage/retrieval system impacts process flow time (and that the consultant wasn’t worth the money). Do you agree with this conclusion? Explain.
=+a) Is this an experiment or observational study? Explain.
=+c) How many treatments are involved?M20_SHAR8696_03_SE_C20.indd 765 14/07/14 7:37 AM 766 CHAPTER 20 Design and Analysis of Experiments and Observational Studies
=+that their relative inexperience may also be contributing to the variation. Three parts were randomly selected and measured from each treatment combination. The deviation from specified size was measured in microns. The data and two-way ANOVA results are shown.Size Error Machine Setting Shift
=+41. Production problems. A manufacturing company that makes dental drills was experiencing problems with a specific part on the production line. Management suspected a machining problem that resulted in the length of the part varying outside of target specification. Two factors were examined:
=+c) How does the upper limit compare to the upper limit in Exercise 7, part c?Chapter Exercises
=+9. Super Glue®. Cyanoacrylates, the generic name for several compounds with strong adhesive properties, were invented during WWII during experiments to make a special extraclear plastic suitable for gun sights. They didn’t work for gun sights, however, because they stuck to everything. They
=+c) If so, perform the hypothesis tests and state your conclusions in terms of compressive strength, alkali content, and sand type.
=+samples were randomly selected from each treatment combination to be tested. The boxplots show the test results on compressive strength (in psi) for the three levels of alkali content and three types of sand. Two-way ANOVA results are also given.H L M Alkali Content 2000 2200 2400 2600 2800 3000
=+40. Concrete testing. A company that specializes in developing concrete for construction strives to continually improve the properties of its materials. To increase the compressive strength of one of its new formulations, they varied the amount of alkali content (low, medium, high). Since the
=+Krazy® Glue. They are often sold in small quantities, typically 2-oz. tubes. The manufacturers want to ensure that the same quantity of glue goes into each tube so they monitored the process from the past three weeks (when there were no production problems) and calculate the mean and standard
=+d) Is it appropriate to interpret the main effects in this case? Explain.
=+c) If so, perform the hypothesis tests and state your conclusions in terms of hourly wages, occupational type, and region.
=+b) Are the conditions for two-way ANOVA met?
=+39. Managers’ hourly wages. What affects marketing managers’ hourly wages? To find out, mean hourly wages were retrieved from the U.S. Bureau of Labor Statistics for two managerial occupations in marketing (Sales managers, Advertising managers) for a random sample of states from three
=+10. The R&A. The R&A requires that a golf ball used in a major league game have a diameter between 42 mm and 42.67 mm. Ben Hogan® is an official supplier of golf balls to the world golfing market. In their production process, do they treat 42 and 42.67 mm. as control or specification limits?
=+c) Given the small P-value associated with the gender and that the mean annual bonus percent for females is 12.5%compared to 14.5% for males, HR concludes that gender discrimination exists. Do you agree? Explain.
=+38. Company bonuses. After complaints about gender discrimination regarding bonus incentive pay, a large multinational firm collected data on bonuses awarded during the previous year (% of base pay). Human Resources (HR)randomly sampled male and female managers from three different levels:
=+e) What does the interaction term test and what do you conclude about that?
=+d) What do you conclude about the average value of the DJIA in different months? Explain.
=+DJIA on different days of the week? Explain.
=+11. Pole vault. Pole vault technology has evolved considerably since the times of the ancient Greeks and even more recently as new materials have found their way into pole manufacturing. There are currently no regulations on the composition of poles although for safety reasons, there are
=+c) What do you conclude about the average value of the
=+b) State the hypotheses.
=+37. Stock patterns. Some people believe that the stock market shows patterns according to the day of the week or the month of the year (“Sell in May and walk away”). We have the closing price of the Dow Jones Industrial Average for every day from January 2009 through February 2013. Here is
=+c) What are the factors?
=+a) Is this an experiment or an observational study? Explain.
=+less than 6.0 m wide and 6.15 m long. Should the manufacturers of landing pads treat these as specification or control limits? Explain.
=+36. Injection molding. To improve the quality of molded parts, companies often test different levels of parameter settings to find the best combinations. Injection molding machines typically have many adjustable parameters. One company used three different mold temperatures (25, 35, and 45
=+e) State the hypotheses (in words, not symbols).
=+12. Milk production. Whether pasteurized or raw, both the European Economic Council (EEC) and the U.S. Food and Drug Administration (USFDA) require that milk sold to consumers contain no more than 10 coliform bacteria per mL of milk (www.cdfa.ca.gov). Should dairies take this as a control or
=+d) How many treatments are involved?
=+c) How many factors are involved?
=+a) Is this an experiment or an observational study?Explain.
=+a transaction involving one of three products (book, camera, or insurance). These products represent varying degrees of risk. After completing the transaction, they rated how“trustworthy” the website was on a scale of 1 (not at all) to 10 (extremely trustworthy).
=+35. E-trust. Online retailers want customers to trust their websites and want to alleviate any concerns potential customers may have about privacy and security. In a study investigating the factors that affect e-trust, participants were randomly assigned to carry out online transactions on
Showing 1000 - 1100
of 6217
First
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Last
Step by Step Answers
Get 50% OFF
Claim Now
