Consider the following study:A recent Brazilian study enrolled patients who had had symptoms of Covid-19 for aweek but were not hospitalized. The study randomly assigned them to receive thedrug ivermectin once daily for three days or a placebo. The medical staff and patientswere unaware of the randomized assignments. Overall, 100 patients (14.7%) in theivermectin group were later hospitalized due to Covid-19, compared with 111 (16.3%)in the placebo group -- a negligible difference (not statistically significant).This study is an example of:a cross-sectional sample surveya longitudinal cohort studya completely randomized experimentan unscientific study with voluntary sample or anecdotal dataan experiment with matched pairs/repeated measuresa census (population data)a case-control observational studyWhat is the response variable, and is it quantitative or categorical?Enter your answer here

The response variable in this study is hospitalization due to Covid-19, which is a categorical…

Answered: Consider the following study: A recent…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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A 2012 article in the New England Journal reports the results of a randomized trial to assess the association between regular usage of asthma medication prior to turning 18 years old, and height at age 18 years. As per the authors, "From December 1993 through September 1995, we randomly assigned 1041 children between the ages of 5 and 13 years with mild-to-moderate asthma to one of three study groups in the double-blind, placebo-controlled CAMP trial." (reference: Kelly H, et al. Effect of Inhaled Glucocorticoids in Childhood on Adult Height. New England of Medicine (2012). 367 (10)) The random assignment groups were Budesonide, Nedocromil and placebo. The following graphic shows the distribution of female and male participant heights at different times in the study follow-up, presented for the Budesonide and placebo samples. A Unadjusted Height Distribution 200 I Budesonide I Placebo 190 180- 170- 160- 150- 140- 130- 120- 110- 100- 0- Trial entry 2 Yr Trial end Adult Trial entry 2 Yr…
Researchers investigate how the presence of cell phones influence the quality of human interaction. Subjects are randomly selected from a population and divided into an experimental group that is asked to leave their phones in the front of the room and a control group that are not asked to leave their cell phones at the front of the room. Subjects are left alone for 10 minutes and then asked to take a survey designed to measure quality of interactions they had with others in the experiment. What statistical test is appropriate?
Vitamin E and the Risk of Prostate Cancer: Klien et al (2011) conducted the following study to determine the effect of vitamin E and selenium treatment on the risk of developing prostate cancer in healthy men. A total of 34,887 men from different study sites in the United States, Canada, and Puerto Rico were randomly selected. To be eligible to participate, the men had to take a rectal examination that showed he was not suspicious of having prostate cancer and be aged 50 years or older for black men and 55 years or older for all others. Each man was randomly assigned to receive one of four treatments: selenium, vitamin E, selenium and vitamin E together, or a placebo. The men were followed up after 8 years to see if they had developed prostate cancer or not. The main question of interest is to determine if the risk of developing prostate cancer differs by the treatment taken. The data are summarized in the table below: No Prostate Cancer Prostate Cancer Total Selenium 8,752 8,737 8,702…
In randomized, double-blind clinical trials of a new vaccine, children were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the second dose, 125 of 746 subjects in the experimental group (group 1) experienced fever as a side effect. After the second dose, 82 of 627 of the subjects in the control group (group 2) experienced fever as a side effect. Does the evidence suggest that a higher proportion of subjects in group 1 experienced fever as a side effect than subjects in group 2 at the a= 0.01 level of significance? Find the test statistic for this hypothesis test. (Round to two decimal places as needed.)
High levels of cholesterol in the blood are associated with higher risks of heart attacks. Will using a drug to lower blood cholesterol reduce heart attacks? The Helsinki Heart Study recruited middle-aged men with high cholesterol but no history of other serious medical problems to investigate this question. The volunteer subjects were assigned at random to one of the two treatments: 2051 men took the drug gemfibrozil to reduce their cholesterol levels, and a control group of 2030 men took a placebo. During the next five years, 56 men in the gemfibrozil group and 84 in the placebo group had heart attacks. Is the difference statistically significant at the alpha = 0.01 level?
ester Hollar is vice president for human resources for a large manufacturing company. In recent years, he has noticed an increase in absenteeism that he thinks is related to the general health of the employees. Four years ago, in an attempt to improve the situation, he began a fitness program in which employees exercise during their lunch hour. To evaluate the program, he selected a random sample of eight participants and found the number of days each was absent in the six months before the exercise program began and in the six months following the exercise program. Below are the results. Employee Before After 1 6 5 2 6 2 3 7 1 4 7 3 5 4 3 6 3 6 7 5 3 8 6 7 At the 0.05 significance level, can he conclude that the number of absences has declined? Estimate the p-value. State the decision rule for 0.05 significance level. (Round your answer to 3 decimal places.) Compute the test statistic. (Round your answer to 3 decimal places.)
In a study on the effect of an oral rinse on plaque buildup on teeth, sixteen people whose teeth were thoroughly cleaned and polished were randomly assigned to two groups of eight subjects each. Both groups were assigned to use oral rinses (no brushing) for a 2-week period. Group 1 used a rinse that contained an antiplaque agent. Group 2, the control group, received a similar rinse except that the rinse contained no antiplaque agent. A measure of plaque buildup was recorded at 14 days with means and standard deviations for the two groups shown in the table. Control Group Antiplaque Group Sample Size 8 8. Mean 1.22 0.77 Standard Deviation 0.33 0.33 n USE SALT (a) State the null and alternative hypotheses that should be used to test the effectiveness of the antiplaque oral rinse. O Ho: (H, - H2) = 0 versus H: (, - H2) 0 O Ho: (H1 - H2) = 0 versus H,: (H, - H2) > 0 O Ho: (H1 - H2) = 0 versus H.: (4, - H2) # 0 (b) Do the data provide sufficient evidence to indicate that the oral…
Answer the following:
Most cases of cervical cancer are linked to a few strains of the human papilloma virus (HPV). The pharmaceutical company Merck developed a vaccine (Gardisil) against these HPV strains. Worldwide clinical trials followed young women after vaccination or administration of placebo for two to four years for signs of HPV-caused cervical cancer. Based on a sample of 100 women in the Gardisil group, 24 % developed cervical cancer, and based on a sample of 100 women in the placebo group, 34 % developed cervical cancer. Test the claim that the proportion of women who developed cervical cancer in the Gardisil group is less than the proportion of women who developed cervical cancer in the placebo group at a = 0.10. Round your answers to three decimal places, and round any interim calculations to four decimal places. Fill in the hypotheses below where p₁ denotes the proportion of women who developed cervical cancer in the Gardisil group and P2 denotes the proportion of women who developed cervical…
A researcher conducts a between-subjects study to determine whether low levels of the neurochemical serotonin leads to an increase in aggression. One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin. A second sample of rats receives a drug that lowers brain levels of serotonin. Using an alpha level of a = .05, the researcher then tests the animals by recording the number of aggressive responses each of the rats display. The data are as follows: a.) Step 1: State the Hypotheses Ho: H₁: Control n = 10 M = 14 SS=180.5 b.) Step 2: Determine the critical region and draw it on the distribution above: df = > *critical SM₁-M₂ Low Serotonin n = 15 M = 19 SS = 130.0 c.) Step 3: Calculate the test statistic using the provided sample data: tobs d.) Step 4: Make a decision. Circle one: Reject Null (Ho) or Fail to Reject Null (Ho) e.) State your conclusions about the research scenario in sentence form: d= f.) What is the estimated effect…
In the Utah study, among participants who reported contact with a family member with known SARS-COV-2 infection, 14.4 % were seropositive. In your area, you are noticing a similar trend. Based on your study with your team, you have determined that among the 100 people in your sample who reported contact with a family member with known SARS-CoV-2 infection, 20% of the individuals were seropositive. Answer the following questions about your study: (a) What is the n? (b) What is the p (use two places after the decimal)? (c) What is the q (use two places after the decimal)? (d) What is the expected value for 100 seropostive cases? (e) What is the variance for 100 seropositive cases?

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