STATS:DATA+MODELS-W/DVD
4th Edition
ISBN: 9780321986498
Author: DeVeaux
Publisher: PEARSON
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Chapter 12.4, Problem 2JC
a.
To determine
Explain the meaning for the experiment to be double blind.
b.
To determine
Explain the use of placebo for the given study.
c.
To determine
Explain the way to design an experiment to balance the patients who had recently developed peptic ulcer and who had peptic ulcer from long time.
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very time you conduct a hypothesis test, there are four possible outcomes of your decision to reject or not reject the null hypothesis: (1) You don’t reject the null hypothesis when it is true, (2) you reject the null hypothesis when it is true, (3) you don’t reject the null hypothesis when it is false, and (4) you reject the null hypothesis when it is false.
Consider the following analogy: You are an airport security screener. For every passenger who passes through your security checkpoint, you must decide whether to select the passenger for further screening based on your assessment of whether he or she is carrying a weapon. Suppose your null hypothesis is that the passenger has a weapon. As in hypothesis testing, there are four possible outcomes of your decision: (1) You select the passenger for further inspection when the passenger has a weapon, (2) you allow the passenger to board her flight when the passenger has a weapon, (3) you select the passenger for further inspection when…
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Ch 6 Sec 4 Homework
Question 4 of 4 (1 point) | Question Attempt: 2 of Unlimited
✓ 2
✓ 3
= 4
Stress at work: In a poll conducted by the General Social Survey, 81% of respondents said that their jobs were sometimes or always stressful. Two hundred
workers are chosen at random. Use the TI-84 Plus calculator as needed. Round your answer to at least four decimal places.
(a) Approximate the probability that 155 or fewer workers find their jobs stressful.
(b) Approximate the probability that more than 145 workers find their jobs stressful.
(c) Approximate the probability that the number of workers who find their jobs stressful is between 154 and 172 inclusive.
Part 1 of 3
The probability that 155 or fewer workers find their jobs stressful is 0.1207
Part 2 of 3
bility that more than 145 workers find their jobs…
A case-control (or retrospective) study was conducted to investigate a relationship between the colors of helmets worn by motorcycle drivers and whether they are injured or killed in a crash. Results are given in the accompanying table. Using a 0.01
significance level, test the claim that injuries are independent of helmet color.
Color of Helmet
Black
White
Yellow
Red
Blue
Controls (not injured)
499
373
32
159
79
Cases (injured
221
108
8
66
38
or killed)
Click here to view the chi-square distribution table.
Chi-square distribution table
Area to the Right of the Critical Value
Degrees of
Freedom
0.995
0.99
0.975
0.95
0.90
0.10
0.05
0.025
0.01
0.005
C. Ho: Injuries and neimet color are dependent
H₁: Injuries and helmet color are independent
D. Ho: Whether a crash occurs and helmet color are dependent
1
0.001
0.004
0.016
2.706
3.841
5.024
6.635
7.879
2
0.010
0.020
0.051
0.103
0.211
4.605
5.991
7.378
9.210
10.597
3
0.072
0.115
0.216
0.352
0.584
6.251
7.815
9.348
11.345
12.838
4
0.207
0.297…
Chapter 12 Solutions
STATS:DATA+MODELS-W/DVD
Ch. 12.3 - 1. At one time, a method called “gastric freezing”...Ch. 12.4 - Prob. 2JCCh. 12 - Prob. 1ECh. 12 - 2. E-commerce A business student conjectures that...Ch. 12 - 3. Tips A pizza delivery driver, always trying to...Ch. 12 - 4. Tomatoes You want to compare the tastiness and...Ch. 12 - 5. Tips II For the experiment described in...Ch. 12 - 6. Tomatoes II For the experiment described in...Ch. 12 - 7. Tips again For the experiment of Exercise 3,...Ch. 12 - 8. Tomatoes again For the experiment of Exercise...
Ch. 12 - 9. More tips Is the experiment of Exercise 3...Ch. 12 - 10. More tomatoes If the tomato taster doesn’t...Ch. 12 - 11. Block that tip The driver of Exercise 3 wants...Ch. 12 - 12. Blocking tomatoes To obtain enough plants for...Ch. 12 - 13. Confounded tips For the experiment of Exercise...Ch. 12 - 14. Tomatoes finis What factors might confound the...Ch. 12 - 15. Standardized test scores For his statistics...Ch. 12 - 16. Heart attacks and height Researchers who...Ch. 12 - 17. MS and vitamin D Multiple sclerosis (MS) is an...Ch. 12 - 18. Super Bowl commercials When spending large...Ch. 12 - Prob. 19ECh. 12 - 20. Honesty Coffee stations in offices often just...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 21–34. What’s the design? Read each brief report...Ch. 12 - 35. Omega-3 Exercise 21 describes an experiment...Ch. 12 - 36. Insomnia Exercise 24 describes an experiment...Ch. 12 - 37. Omega-3, revisited Exercises 21 and 35...Ch. 12 - 38. Insomnia, again Exercises 24 and 36 describe...Ch. 12 - 39. Omega-3, finis Exercises 21, 35, and 37...Ch. 12 - 40. Insomnia, at last Exercises 24, 36, and 38...Ch. 12 - 41. Injuries Exercise 33 describes an experiment...Ch. 12 - 42. Tomatoes II Describe a strategy to randomly...Ch. 12 - 43. Shoes A running-shoe manufacturer wants to...Ch. 12 - 44. Swimsuits A swimsuit manufacturer wants to...Ch. 12 - 45. Hamstrings Exercise 33 discussed an experiment...Ch. 12 - 46. Diet and blood pressure An experiment showed...Ch. 12 - Prob. 47ECh. 12 - 48. Contrast baths Contrast bath treatments use...Ch. 12 - Prob. 49ECh. 12 - 50. Swimming Recently, a group of adults who swim...Ch. 12 - 51. Dowsing Before drilling for water, many rural...Ch. 12 - 52. Healing A medical researcher suspects that...Ch. 12 - 53. Reading Some schools teach reading using...Ch. 12 - 54. Gas mileage Do cars get better gas mileage...Ch. 12 - 55. Weekend deaths A study published in the New...Ch. 12 - 56. Shingles A research doctor has discovered a...Ch. 12 - 57. Beetles Hoping to learn how to control crop...Ch. 12 - 58. SAT prep Can special study courses actually...Ch. 12 - 59. Safety switch An industrial machine requires...Ch. 12 - 60. Washing clothes A consumer group wants to test...Ch. 12 - 61. Skydiving, anyone? A humor piece published in...
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Similar questions
- Conduct the hypothesis test and provide the test statistic and the critical value, and state the conclusion. A person drilled a hole in a die and filled it with a lead weight, then proceeded to roll it 200 times. Here are the observed frequencies for the outcomes of 1, 2, 3, 4, 5, and 6, respectively: 28, 32, 46, 39, 29, 26. Use a 0.025 significance level to test the claim that the outcomes are not equally likely. Does it appear that the loaded die behaves differently than a fair die? Click here to view the chi-square distribution table. The test statistic is (Round to three decimal places as needed.) Chi-square distribution table Area to the Right of the Critical Value Degrees of Freedom 0.995 0.99 0.975 0.95 0.90 0.10 0.05 0.025 0.01 0.005 1 0.001 0.004 0.016 2.706 3.841 5.024 6.635 2 0.010 0.020 0.051 0.103 0.211 4.605 5.991 7.378 9.210 7.879 10.597 3 0.072 0.115 0.216 0.352 0.584 6.251 7.815 9.348 11.345 12.838 4 0.207 0.297 0.484 0.711 1.064 7.779 9.488 11.143 13.277 14.860 5…arrow_forwardThe online clothing retailer e-Parel is conducting a study to estimate the average size of the orders placed by visitors to its website. The project manager desires a $60 bound on the error of estimation at 90% confidence. The population standard deviation is unknown, and a “best guess” of $175 is used as the planning value for σ. Use the Distributions tool to help you answer the questions that follow. 0123 Select a Distribution The z-value for a 90% confidence interval of the population mean is . In order to satisfy the requirement of a $60 bound on the error of estimation, a sample size no smaller than is needed.arrow_forwardA local electronics store just received a shipment of 620 HDMI cables. The manager wants to estimate the number of defective HDMI cables in the shipment. Rather than checking every HDMI cable, the manager plans to take a simple random sample of size 62 in order to estimate the proportion of defective HDMI cables in the shipment. If the sample proportion of defective HDMI cables, p̂p̂, is greater than 0.0323 (there are more than two defective HDMI cables in the sample), the manager will file a complaint and request a new shipment. Suppose that the true proportion of defective HDMI cables in the shipment is approximately p = 0.02. What is the expected value of the sample proportion? E(Pˆ)E(P^)= Since the sample is to be drawn from a finite population, and since the sample is 5% of the population size, the finite population correction factor needed when you calculate the standard deviation of the sampling distribution. What is the standard deviation of the…arrow_forward
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