Concept explainers
In 2006, Boston Scientific sought approval for a new heart stent (a medical device used to open clogged arteries) called the Liberte. This stent was being proposed as an alternative to a stent called the Express that was already on the market. The following excerpt is from an article that appeared in The Wall Street Journal (August 14, 2008):
Boston Scientific wasn’t required to prove that the Liberte was ‘superior’ than a previous treatment, the agency decided—only that it wasn’t ‘inferior’ to Express. Boston Scientific proposed—and the FDA okayed—a benchmark in which Liberte could be up to three percentage points worse than Express—meaning that if 6% of Express patients’ arteries reclog, Boston Scientific would have to prove that Liberte’s rate of reclogging was less than 9%. Anything more would be considered 'inferior.’… In the end, after nine months, tire Atlas study found that 85 of the patients suffered reclogging. In comparison, historical data on 991 patients implanted with the Express stent show a 7% rate. Boston Scientific then had to answer this question: Could the study have gotten such results if the Liberte were truly inferior to Express?”
Assume a 7% reelogging rate for the Express stent. Explain why it would be appropriate for Boston Scientific to carry out a hypothesis test using the following hypotheses:
H0: p = 0.10
Ha: p < 0.10
where p is the proportion of patients receiving Liberte stents that suffer reclogging. Be sure to address both the choice of the hypothesized value and the form of the alternative hypothesis in your explanation.
Trending nowThis is a popular solution!
Chapter 10 Solutions
Introduction To Statistics And Data Analysis
- A study published in JAMA in 2004 examined past results of other studies on bariatric surgery. Bariatric surgery is done to replace the size of the stomach in various ways. It is typically used on only obese patients, and one the traditional form of the surgery, gastric bypass has a 1% mortality (death) rate caused by the surgery. However, in the studies reporting on the effects of this surgery on Type II diabetes, 1417 of 1846 diabetic patients recovered completely from diabetes after surgery. These patients no longer need medication like insulin (which is injected into the skin) or pills to help manage blood sugar. In a study released a decade later, the percentage of patients who recover from diabetes has increased to 80%. W will determine whether this is a significant change from the 2004 data. The sample size in 2014 was 2000. (a) What is the percentage of patients who recovered from diabetes in 2014? What is the number of patients in the sample that have recovered? (b) What…arrow_forwardYou are working for Wildcat Microwaveable Meals, a food prep company designed specifically to deliver microwaveable meals to overworked Wildcats. You are trying to decide if it is still worth offering the "Kale Salad" option, since it seems like students are not ordering microwaveable salads like they used to. Previously, you had about 50 kale salad orders a week, but in the last 10 weeks, you've noticed it's only been an average of 40 kale salad orders with a standard deviation of 5 orders. You decide to conduct a hypothesis test to evaluate if kale salad orders are decreasing, and you decide to use the 0.01 significance level. What will your alternative hypothesis bearrow_forwardA serious side effect of allergy medicines is that they cause drowsiness, which can cause many problems for the individuals taking them. In recent years, a new non-drowsy allergy medicine has been developed. The company that created the medicine claims to be the first, once-a-day, non-drowsy allergy medicine (call it Medicine A). An independent research group wanted to check on this claim by comparing Medicine A with another allergy medicine not advertised as non-drowsy (call it Medicine B). A random sample of 3,193 allergy sufferers was selected and each individual was randomly assigned to take either Medicine A or Medicine B. From the Medicine A group, 114 of 1,604 reported drowsiness and from the Medicine B group, 155 of 1,589 reported drowsiness. a) Calculate and label the two sample proportions separately. Next, calculate the difference between these sample proportions by subtracting (Medicine A – Medicine B). Complete these calculations by hand, label each of them, and present…arrow_forward
- A serious side effect of allergy medicines is that they cause drowsiness, which can cause many problems for the individuals taking them. In recent years, a new non-drowsy allergy medicine has been developed. The company that created the medicine claims to be the first, once-a-day, non-drowsy allergy medicine (call it Medicine A). An independent research group wanted to check on this claim by comparing medicine A with another allergy medicine not advertised as non-drowsy (call it Medicine B). A random sample of 3,193 allergy sufferers was selected and each individual was randomly assigned to take either Medicine A or Medicine B. From the Medicine A group, 114 of 1,604 reported drowsiness and from the Medicine B group, 155 of 1,589 reported drowsiness. Calculate and label the two sample proportions separately. Next, calculate the difference between these sample proportions by subtracting (Medicine A – Medicine B). Complete these calculations by hand, label each of them, and…arrow_forwardThe owner of a small firm has just purchased a personal computer, which she expects will serve her for the next two years. The owner has been told that she "must buy a surge suppressor to provide protection for her new hardware against possible surges or variations in the electrical current, which have the capacity to damage the computer. The amount of damage to the computer depends on the strength of the surge. It has been estimated that there is a 3% chance of incurring 450 dollar damage, 4% chance of incurring 250 dollar damage, and 15% chance of 75 dollar damage. An inexpensive suppressor, which would provide protection for only one surge, can be purchased. How much should the owner be willing to pay if she makes decisions on the basis of expected value? Expected Value =arrow_forwardArthritis is a very commonly occurring affliction. It is a major cause of lost work time and often results in serious disability. Of the many types of arthritis, the most common type is osteoarthritis. This condition is frequently due to wear and tear in the joints and is more likely to be found in people over 50. It is very painful in the weight-bearing joints, such as the knees and hips. Cartilage wears away on the bone ends, causing pain and swelling. Osteoarthritis may develop after an injury such as a bone fracture or a joint dislocation. To reduce the amount of time osteoarthritis patients are absent from work, it is important for them to have effective pain relief. An experiment was conducted to compare the effectiveness of three new analgesics: A1, A2, and A3. A clinic evaluated a large group of patients and identified 45 patients with a moderate level of pain. Fifteen of the 45 persons were then randomly assigned to one of the three analgesics. The patients were then…arrow_forward
- "The US Centers for Disease Control and Prevention said about 72 million Americans-nearly one out of every four of the country's 304 million residents-are considered obese. Millions more are designated as overweight." The American trend toward obesity has prompted many physicians to offer weight-loss programs to their patients. [Source: Price, w. T. "Physicians Get into the Weight-Loss Business." Florida Today, July 7, 2008.] A physician conducted an experimental study to compare the effectiveness of four different weight-loss programs. In the study, 60 obese adults were randomly assigned to the four programs so that each program had 15 adults. The programs lasted for six months. The weights of the subjects were measured before and after the programs, and each subject's weight loss was computed in pounds. The following table summarizes the results of the study, giving the number of observations and the sample mean and variance of the subjects' weight loss in each program. Treatment…arrow_forwardIn August and September 2005 , Hurricanes Katrina and Rita caused extraordinary flooding in New Orleans, Louisiana. Many homes were severely damaged or destroyed, and of those that survived, many required extensive cleaning. It was thought that cleaning flood-damaged homes might present a health hazard due to the large amounts of mold present in many of the homes. In a sample of 350 residents of Orleans Parish who had participated in the cleaning of one or more homes, 50 had experienced symptoms of wheezing, and in a sample of 176 residents who had not participated in the cleaning, 42 reported wheezing symptoms (numbers read from a graph). Can you conclude that there is a difference between the proportion of residents with wheezing symptoms who cleaned flood-damaged homes and those who did not participate in the cleaning? Let p1 denote the proportion of residents with wheezing symptoms who had cleaned flood-damaged homes and p2 denote the proportion of…arrow_forwardA study published in JAMA in 2004 examined past results of other studies on bariatric surgery. Bariatric surgery is done to replace the size of the stomach in various ways. It is typically used on only obese patients, and one the traditional form of the surgery, gastric bypass has a 1% mortality (death) rate caused by surgery. However, in the studies reporting on the effects of the surgery on Type ll diabetes, 1417 of 1846 diabetic patients recovered completely from diabetes after surgery. These patients no longer need medication like insulin (which is injected into the skin) or pills to help manage blood sugar. If you had a morbidly obese relative with diabetes what would you tell him or her about bariatric surgery? Explain. Would you recovered it? Why/ why not?arrow_forward
- A study published in JAMA in 2004 examined past results of other studies on bariatric surgery. Bariatric surgery is done to replace the size of the stomach in various ways. It is typically used on only obese patients, and one the traditional form of the surgery, gastric bypass has a 1% mortality (death) rate caused by surgery. However, in the studies reporting on the effects of the surgery on Type ll diabetes, 1417 of 1846 diabetic patients recovered completely from diabetes after surgery. These patients no longer need medication like insulin (which is injected into the skin) or pills to help manage blood sugar. In a study released a decade later, the percentage of patients who recover from diabetes has increased 80%. Using confidence intervals determine whether this is a significant change from the 2004 data. Use n=2000arrow_forwardSleep apnea is a condition in which the sufferers stop breathing momentarily while they are asleep. This condition results in lack of sleep and extreme fatigue during waking hours. A current estimate is that 10 million out of the 312.7 million Americans suffer from sleep apnea, or approximately 3.2%. A safety commission is concerned about the percentage of commercial truck drivers who suffer from sleep apnea. They do not have any reason to believe that it would be higher or lower than the population’s percentage. To test the claim that the percentage of commercial truck drivers who suffer from sleep apnea is not 3.2%, a simple random sample of 409 commercial truck drivers is examined by a medical expert, who concludes that 21 suffer from sleep apnea. Does this evidence support the claim that the percentage of commercial truck drivers who suffer from sleep apnea is not 3.2%? Use a 0.05 level of significance. Step 2 of 3 : Compute the value of the test statistic. Round your…arrow_forwardSleep apnea is a condition in which the sufferers stop breathing momentarily while they are asleep. This condition results in lack of sleep and extreme fatigue during waking hours. A current estimate is that 15 million out of the 312.7 million Americans suffer from sleep apnea, or approximately 4.8%. A safety commission is concerned about the percentage of commercial truck drivers who suffer from sleep apnea. They do not have any reason to believe that it would be higher or lower than the population’s percentage. To test the claim that the percentage of commercial truck drivers who suffer from sleep apnea is not 4.8%, a simple random sample of 339 commercial truck drivers is examined by a medical expert, who concludes that 7 suffer from sleep apnea. Does this evidence support the claim that the percentage of commercial truck drivers who suffer from sleep apnea is not 4.8%? Use a 0.05 level of significance. Step 3 of 3 : Draw a conclusion and interpret the decision.…arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman