Concept explainers
Neutropenia. Neutropenia is an abnormally low number of neutrophils (a type of white blood cell) in the blood. Chemotherapy often reduces the number of neutrophils to a level that makes patients susceptible to fever and infections. G. Bucaneve et al. published a study of such cancer patients in the paper “Levofloxacin to Prevent Bacterial Infection in Patients With Cancer and Neutropenia” (New England Journal of Medicine, Vol. 353, No. 10, pp. 977-987). For the study, 375 patients were randomly assigned to receive a daily dose of levofloxacin, and 363 were given placebo. In the group receiving levofloxacin, fever was present in 243 patients for the duration of neutropenia, whereas fever was experienced by 308 patients in the placebo group.
- a. At the 1% significance level, do the data provide sufficient evidence to conclude that levofloxacin is effective in reducing the occurrence of fever in such patients?
- b. Find a 98% confidence level for the difference in the proportions of such cancer patients who would experience fever for the duration of neutropenia.
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Introductory Statistics (10th Edition)
- One variety of corn is genetically modified to produce chemicals for defense against predators. The standard corn contains the same standard genotype, but without genetic modification for the chemicals. The two types of corn are then planted in randomly placed adjacent plots across a single field. The amount of predators that are present when the corn has matured are then recorded. The data that was recorded of the predators present among each type are listed. Has genetic alterations decreased the amount of predators for the altered genotype? Normality tests for the populations of both contain a p value less than 0.05. The given alpha is 0.05 Modified Corn (20, 18, 26, 23, 17, 23, 22) Standard Corn (89, 64, 102, 96, 56, 77, 84, 59) use an F test to determine if the variance between the 2 lists are different. Based on this result, state the correct 2 sample parametric test to be used. State the null and alternative. Show calculations while rounding to two decimal points.What is the…arrow_forwardA mutation in Gene A is thought to be associated with a disease. The mutation in Gene A is found in 5% of the population. 2% of the whole population is diagnosed with disease B at some point in their life time. 1% of the population both has the mutation and also gets diagnosed with the disease in their life time. Is the provided data adequate to test the independency of mutation in Gene A and occurrence of Disease B? If it is not, what other information or data is needed to test the independency? What is the probability of Disease B, among the individuals with the mutation in Gene A? What is the probability of having the mutation in Gene A among the individuals with Disease B? If an individual has the mutated Gene A, what is their Relative Risk of developing the disease?arrow_forward4. Captopril is a drug designed to lower systolic blood pressure. When subjects were treated with this drug, their systolic blood pressure readings (in mm Hg) were measured before and after the drug was taken. Results are given in the accompanying table (based on data from “Essential Hypertension: Effect of an Oral Inhibitor of Angiotensin-Converting Enzyme”, by MacGregor et al., BMJ, Vol. 2). Using a 0.01 significance level, is there sufficient evidence to support the claim that captopril has an effect on systolic blood pressure? Explain why statistical methods from Z-interval, Z-test, T-interval or T-test –cannot be used for this problem. Then, use the sign test to conduct the required test in R studio. Please show your work.arrow_forward
- A recent study set out to investigate the association between smoking and the development of coronary artery disease (CAD), the leading cause of heart attacks among adults in the US. Upon enrollment in the study, 1,232 adult participants were asked to report whether they had ever smoked more than one pack of cigarettes in the lifetimes. The participants were then examined for the development of CAD once a year for the following twenty years. Examinations found 106 cases of CAD among the 368 participants who had never smoked and 419 cases of CAD among the 864 participants who had ever smoked. 6) What type of study design was used? Explain. 7) Set up the 2X2 contingency table for the data. 8) For this type of study design, what is the appropriate measure to describe the strength of the association between the exposure and the disease? 9) Calculate the measure identified in question 8. 10) Interpret the measure calculated in question 9.arrow_forwardIn 1992, the U.S. Public Health Service and the Centres for Disease Control and Prevention recommended that all women of childbearing age consume 400mg of folic acid daily to reduce the risk of having a pregnancy that is affected by a neural tube defect such as spina bifida or anencephaly. In a study by Stepanuk et al. (A-3), 693 pregnant women called a teratology information service about their use of folic acid supplementation. The researchers wished to determine if preconceptional use of folic acid and race are independent. The data appear in Table below: Total Preconceptional Use of Folic Acid Race No Yes 559 299 260 White 56 41 15 Black 21 14 7 Other 636 354 282 Total Test the hypothesis that there is no association between the usage of folic acid and race with 5% significant level and using SPSS (Choose only 4 correct answers from the following statements): 1. The null and alternative hypothesis are: H0: The two variables are dependent. H1: The two…arrow_forwardVariegated Plants.Arabidopsis is a genus of flowering plant related to cabbage. A variegated mutant of the Arabidopsis has yellow streaks or marks. E. Miura et al. studied the origin of this variegated mutant in the article “The Balance between Protein Synthesis and Degradation in Chloroplasts Determines Leaf Variegation in Arabidopsis yellow variegated Mutants” (The Plant Cell, Vol. 19, No. 4, pp. 1313–1328). In a second-generation cross of variegated plants, 216 were variegated and 84 were normal. Genetics predicts that 75% of crossed variegated plants would be variegated and 25% would be normal. At the 10% significance level, do the data provide sufficient evidence to conclude that the second generation of crossed variegated plants does not follow the genetic predictions?arrow_forward
- A recent study investigated the association between sudden cardiac death and smoking history in women from a large health system. The epidemiologist reviewed the electronic health records of women who died from sudden cardiac death (n=80) and women who died of non-cardiac causes (n=80). The investigator then reviewed these records for smoking history (smoking 1+ pack/day and smoking <1 pack/day) and identified the following results. Sudden Cardiac Death 38 42 Smoke 1+ pack/day Smoke <1 pack/day Calculate the most appropriate measure of association for these data (a)-round to the nearest tenth. Other Causes 10 70arrow_forwardA researcher uncovers that there is a significant interaction between the factor of marital status (i.e., married or non-married) and participant sex (i.e., male or female) regarding well-being. A researcher decides to compare the difference in well-being between married men and women. What would be the null hypothesis for this comparison? a. µMale ≠ µFemale for married individuals b. µMale ≠ µFemale for non-married individuals c. µMale = µFemale for non-married individuals d. µMale = µFemale for married individualsarrow_forwardResearchers suspect that drinking tea might enhance the production of interferon gamma, a molecule that helps the immune system fight bacteria, viruses, and tumors. A recent study involved 20 healthy people who did not normally drink tea or coffee. Ten of the participants were randomly assigned to drink five cups of tea a day, while 10 were asked to drink the same amount of coffee. After two weeks, blood samples were exposed to an antigen and production of interferon gamma were measured. The results are shown in the following table: Теа: 55 17 54 49 10 46 21 14 53 Coffee: 16 12 20 52 37 15 22 30 3 Let X ~ N(ux,o3) be the interferon gamma production for participants who drink tea and observations for the ten participants who drink tea are a random sample from X. Let Y ~ N(uy,o) be the interferon gamma production for participants who drink coffee and observations for the ten participants who drink coffee are a random sample from Y. Some R output that may help. > p1 qnorm(p1) [1] -2.326…arrow_forward
- Benzene is a pollutant that, according to studies, can be associated with health problems. Benzene is found in air, water, and soil and comes from both industrial and natural sources. Benzene levels in indoor air are generally higher than outdoors. The main source of benzene in indoor air appears to be tobacco smoke, thus the combustion of tobacco is a major source of pollution. Benzene levels are measured in a random sample of 36 bars in a city, obtaining an average benzene level of 19.2 mg / m3, with a standard deviation of 2.1 mg / m3. Estimate the mean benzene level in bars in this city using a 95% confidence interval. (do your calculations to 4 decimal places) (need the process can be by hand ,Excel or R.) a)Other solution b)[18.48946, 19.91054] c)[19.0950, 19.3050] d)[18.5140, 19.8859] e)[18.6243, 19.7757] f)[18.4315, 19.7936]arrow_forwardA study was made of 425 children who were hospitalized as a result of motor vehicle crashes. Among 300 children who were not using seat belts, 50 were injured severely. Among 125 children using seat belts, 10 were injured severely (based on data from "Morbidity Among Pediatric Motor Vehicle Crash Victims: The Effectiveness of Seat Belts," by Osberg and Di Scala, American Journal of Public Health, Vol. 82, No. 3). For this problem we want to know, is there sufficient sample evidence to conclude, at the 0.05 significance level, that the proportion of severe injuries is higher for children not wearing seat belts? Let pi be the proportion of severe injuries among all children not wearing seatbelts and who were involved in crashes. Let p2 be the proportion of severe injuries among all children wearing seatbelts and who were involved in crashes. Which is the proper expression of Ho? P1 > P2 P1 P2 Calculate p1 to 4 decimal places: Calculate p2 to 4 decimal places: Calculate the pooled sample…arrow_forwardAn investigator collected the following data with respect to the Corona virus cases and death in the United State America. The results are shown in following table. America Date Corona Cases Death 1-Jun-20 22153 730 31-Мay-20 30-Мay-20 29-Мay-20 28-Мay-20 27-Мay-20 26-Мay-20 20350 638 23290 1015 25069 1212 22658 1223 20546 1535 20121 1432 a- Plot scatter diagram between Corona cases and death. b- Find the regression equation of death to Corona cases. c- Estimate the death for 24000 Corona cases.arrow_forward
- Calculus For The Life SciencesCalculusISBN:9780321964038Author:GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.Publisher:Pearson Addison Wesley,