Problem 4. In 2009 (about twelve years ago) clinical trials were conducted for a new vaccine to protect against the HIV virus. There were more than 16,000 volunteers who were randomly assigned to receive either a placebo or the new vaccine. New infections occurred in 51 of the 8,197 individuals given the vaccine. New infections occurred in 74 of the 8,198 who received dummy shots. You are asked to test the hypothesis that the new HIV vaccine is statistically significantly more effective than the placebo at a 95% significance level. The 2009 Journal paper published with these results is available in Canvas.

Problem 4. In 2009 (about twelve years ago) clinical trials were conducted for a new vaccine to protect against the HIV virus. There were more than 16,000 volunteers who were randomly assigned to receive either a placebo or the new vaccine. New infections occurred in 51 of the 8,197 individuals given the vaccine. New infections occurred in 74 of the 8,198 who received dummy shots. You are asked to test the hypothesis that the new HIV vaccine is statistically significantly more effective than the placebo at a 95% significance level. The 2009 Journal paper published with these results is available in Canvas.

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Solve this question please
how do i solve this question?
A psychologist has developed a mental alertness test. She wishes to study the effects (if any) of type of food consumed on mental alertness. Twenty-one volunteers were randomly divided into two groups. Both groups were told to eat the amount they usually eat for lunch at noon. At 2:00 P.M., all subjects were given the alertness test. Group A had a low-fat lunch with no red meat, lots of vegetables, carbohydrates, and fiber. Group B had a high-fat lunch with red meat, vegetable oils, and low fiber. The only drink for both groups was water. The test scores are shown below. Group A 67 93 82 69 76 47 43 58 92 63 52 Group B 70 57 75 59 66 49 55 46 45 91 89 72 Use a 10% level of significance to test the claim that there is no difference in mental alertness distributions based on type of lunch. (a) What is the level of significance? (b) Compute the sample test statistic. (Use 2 decimal places.) (c) Find the P-value of the sample test statistic. (Use 4 decimal places.)
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.)
A pharmaceutical company is testing the effectiveness of its vaccine across two different age brackets. They take a sample and split the participants up into two separate groups. Group A consists of 44 people who are between ages 13 and 18. Group B consists of 58 people between ages 19 and 26. After being administered the vaccine, it was found that 37 people from group A were immune to the virus and 42 people from group B were immune. (this is the same situation from the previous daily) Why do we use the 'pooled proportion' instead of the null hypothesis in the denominator of the test statistic? At a 10% significance level, is there reason to believe there is a difference in vaccine efficacy between Group A and Group B? explain each step
A manufacturer of laptop computers claims that only 1% of their computers are defective. In a sample of 600 computers, it was found that 3% were defective. If the proportion of defectives were really only 1%, there would be than 1 chance in 1000 of getting such a large proportion of defective laptops in the sample. Is there statistically significant evidence against the manufacturer's claim? Why or Why not?
You recently completed an experiment concerning the effects of carbs on happiness. One group of 11 people are assigned a high carb diet, another group of 11 people are assigned a moderate-high carb diet, another group of 11 people are assigned a moderate-low carb diet, and a final group of 11 people are assigned a low carb diet. If I find that I fail to reject the null hypothesis, what might my next step be? Group of answer choices Change my analysis and alpha to make the finding significant and then run post-hoc tests. 1. Run multiple dependent measures t-tests to see if there are any significant differences between particular groups 2. Run multiple independent samples t-tests to see if there are any significant differences between particular groups 3. Change my hypothesis to see if I can find something significant with a different hypothesis for this study 4. Run home and binge-watch Bridgerton because there is nothing else that should be done statistically
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 psychologist has developed a mental alertness test. She wishes to study the effects (if any) of type of food consumed on mental alertness. Twenty-one volunteers were randomly divided into two groups. Both groups were told to eat the amount they usually eat for lunch at noon. At 2:00 P.M., all subjects were given the alertness test. Group A had a low-fat lunch with no red meat, lots of vegetables, carbohydrates, and fiber. Group B had a high-fat lunch with red meat, vegetable oils, and low fiber. The only drink for both groups was water. The test scores are shown below. Group A 75 82 96 54 78 59 67 53 97 85 66 Group B 70 80 79 60 62 71 52 69 64 88 51 74 Use a 10% level of significance to test the claim that there is no difference in mental alertness distributions based on type of lunch. (a) What is the level of significance?State the null and alternate hypotheses. Ho: Distributions are different. H1: Distributions are the same.Ho: Distributions are the same. H1:…
What test should I use for this problem?
In 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…
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, 123 of 460 subjects in the experimental group (group 1) experienced drowsiness as a side effect. After the second dose, 24 of 106 of the subjects in the control group (group 2) experienced drowsiness as a side effect. Does the evidence suggest that a different proportion of subjects in group 1 experienced drowsiness as a side effect than subjects in group 2 at the a = 0.01 level of significance? Determine the null and alternative hypotheses. Choose the correct answer below. A. Ho: P1 =0 versus Ho: P, #0 B. Ho: P =P2 versus H,: P, P2 The test statistic zo is (Round to two decimal places as needed.)