True or False? A cohort study involves a group of individuals who has a disease compared to a similar group without the disease.
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A: Given: n1=34 , n2=33, x1=15.2, x2=19.5, σ1=7.6, σ2=4.8 The hypothesis that can be derived is: H0:…
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Q: I need help with finding the P-value
A: The test statistic is, z=x¯1-x¯2σ12n1+σ22n2=15.2-19.76.8230+4.8234=-4.51.48962424529=-3.0209≈-3.02…
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A: The provided sample means are shown below: Xˉ1=15.2\bar X_1 = 15.2 (For older people) Xˉ2=19.5\bar…
Q: Education influences attitude and lifestyle. Differences in education are a big factor in the…
A: For age 65 and older : Sample Mean 1 (Xˉ1)(\bar X_1) = 15.215.2 Population Standard Deviation…
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A: We have given that Sample size n1= 38 , n2= 37 Sample mean x1 = 15.2%=0.152 x2= 18.1%=0.181 Known…
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True or False? A cohort study involves a group of individuals who has a disease compared to a similar group without the disease.
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- A pharmaceutical company is testing a new drug for a rare disease. In a clinical trial, 1000 patients with the disease were randomly assigned to receive either the new drug or a placebo. After one year, it was found that 60% of the patients who received the new drug experienced improvement, compared to only 40% of those who received the placebo. Is the difference in improvement rates statistically significant? Provide your rationale.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?A study designed to compare two ethnic groups on a measure of a particular personality trait used a large number of participants to have high power. The study found a significant result, but the difference between the means was very small (that is, there was a small effect size). Talk about the fact that this test is statistically significant but may not be practically significant?
- Using the latest in medical technology, an orthopedic doctor has developed a new surgical procedure that he believes is an improvement over the standard procedure. He wants to study whether the mean recovery time of patients who have the new procedure is less than the mean recovery time of patients who have the standard procedure. The doctor studies a random sample of 11 patients who have the new procedure and a random sample of 9 patients who have the standard procedure. (These samples are chosen independently.) The doctor records each patient's recovery time (in days). The patients who had the new procedure have a sample mean recovery time of 367.3 with a sample variance of 2851.8. The patients who had the standard procedure have a sample mean recovery time of 420.9 with a sample variance of 98.1. Assume that the two populations of recovery times are approximately normally distributed. Can the doctor conclude, at the 0.01 level of significance, that the population mean of the…Teenagers who do not sleep well or long enough may have a higher risk of raised blood pressure, which could lead to cardiovascular disease later in life. The odds of raised blood pressure increase 3.5 times for those who have trouble falling asleep at night or who wake up too early and 2.5 times for those with sleeping periods of fewer than 6.5 hours. A health psychologist is interested in studying teenagers who have diastolic blood pressure scores in the top 20%. Diastolic blood pressure scores for teenagers follow a normal distribution with μ = 72 and σ = 10. Use the Distributions tool to help answer the questions that follow. The minimum z-score necessary to be in the top 20% of the diastolic blood pressure distribution is z =0.842 . Use this z-score to determine X, the corresponding diastolic blood pressure score. X = 80.42 This score, X, is the 80th percentile of diastolic blood pressure scores among teenagers. The percentile rank of this score is 80%…Education influences attitude and lifestyle. Differences in education are a big factor in the "generation gap." Is the younger generation really better educated? Large surveys of people age 65 and older were taken in n1 = 38 U.S. cities. The sample mean for these cities showed that x1 = 15.2% of the older adults had attended college. Large surveys of young adults (age 25 - 34) were taken in n2 = 37 U.S. cities. The sample mean for these cities showed that x2 = 18.1% of the young adults had attended college. From previous studies, it is known that ?1 = 6.4% and ?2 = 4.8%. Does this information indicate that the population mean percentage of young adults who attended college is higher? Use ? = 0.05. (c) Find (or estimate) the P-value. (Round your answer to four decimal places.) A random sample of n1 = 12 winter days in Denver gave a sample mean pollution index x1 = 43. Previous studies show that ?1 = 15. For Englewood (a suburb of Denver), a random sample of n2 = 16 winter days gave a…
- In an observational study it was found that people who had received the flu shot this year had better blood pressure readings, on average, than people who did not. Can it be claimed that the flu shot is the cause of the lower overall blood pressure? Why or why not?What conclusions can be drawn from a study with a “statistical significance” result? What information do you look at to evaluate whether an effect obtained in an experiment is large enough to have a “practical” or “clinical” significance?A team of epidemiologists at the Mayo Clinic wanted to find whether there is an association between obesity and cardiovascular disease (CVD). They conducted a prospective cohort study following obese and non-obese individuals who were free of CVD at the beginning of study for five years. The investigators were also interested in assessing age as a potential confounder, effect modifier, or both. Use the data below to answer the accompanying questions. CVD No CVD Total Obese 10 90 100 Not Obese 35 465 500 Total 45 555 600 CVD No CVD Total Obese 36 164 200 Not Obese 25 175 200 Total 61 339 400 1. Compute the appropriate measure of association for those who were less than age 50. 2. Compute the appropriate measure of association for those who were older or equal to age 50. 3. Compute the crude measure of association? 4. List three attributes that age must satisfy before it could…