In a clinical trial to test whether a new drug (treatment) reduces the risk of stroke, the resultsobserved in N=260 subjects is reported below.ObservedTreatment GroupStroke (S = 1)No Stroke (S=0)TotalTreatment (I=1)27108135Placebo (T=0)13112125Total40220260ExpectedTreatment GroupStroke (S = 1)No Stroke (S=0)TotalTreatment (T=1)135Placebo (T=0)125Total40220260Chi-Square CalculationTreatment GroupStroke (S = 1)No Stroke (S=0)Treatment (T=1)Placebo (T=0)Chi-Square4.595

We want to find the expected frequency

Answered: In a clinical trial to test whether a…

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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An investigator is using a chi-square test to compare the proportion of patients with a successful recovery after receiving one of 4 treatments. There were 25 subjects in each group. What is the critical value for testing no association or treatment and response?
Left ventricular mass (LVM) is an important risk factor for subsequent cardiovascular disease. A study is proposed to assess the relationship between childhood blood-pressure levels and LVM in children as determined from echocardiograms. The goal is to stratify children into a normal bp group (< 90th percentile for their age, gender, and height) and an elevated bp group (≥ 90th percentile for their age, gender, and height) and compare change in LVM between the two groups. Before this can be done, one needs to demonstrate that LVM actually changes in children over a 4-year period. To help plan the main study, a pilot study is conducted where echocardiograms are obtained from 10 random children from the Bogalusa Heart Study at baseline and after 4 years of follow-up. The data are given in Table 1 . Table 1 Pilot data on left ventricular mass (LVM) in children from the Bogalusa Heart Study ID Baseline LVM (g) 4- year LVM (g) Change (g)* 1 139 163 24 2 134 126 -8 3 86 142 56…
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Citrus Rental is a popular car rental agency that has a history of having too few cars available, so that its available cars are overdriven. The mean monthly mileage over the years for Citrus cars has been about 1550 miles per month. Recently, though, Citrus purchased thousands of new cars, and the company claims that the average mileage of its cars is now less than in the past. To test this, a random sample of 13 recent mileages of Citrus cars was taken. The mean of these 13 mileages was 1425 miles per month, and the standard deviation was 209 miles per month. Assume that the population of recent monthly mileages of Citrus cars is normally distributed. At the 0.10 level of significance, can it be concluded that the mean recent monthly mileage, μ, of Citrus cars is less than 1550 miles per month? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary,…
A random sample of 50 CSCC students are surveyed to determine what percent of our students are first-generation college students. The results showed that 16 of the students identify as first-generation college students. show your work What is the sample proportion of first-generation college students at CSCC? Is this an example of a parameter or a statistic? Explain.
Here is the scenario for your Between Subjects Independent One Way ANOVA: Dr. Xena is interested in determine which type of therapy best helps persons with bipolar depression. She gathers a random and representative sample of men and women ages 18-95 years of age who have a diagnosis of Bipolar Depression who are taking Lithium for at least 6 months. She randomly assigns participants to conditions and measures well being scores after 4 months of therapy. Well being scores range from 0-100, with 100 being high well-being (feel good and experiencing no mood swings). Here is the data: Cognitive Therapy EMDR Therapy Psychoanalytical Therapy 15 72 28 78 91…
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Research indicates that there may be a relationship between caffeinated coffee consumption and risk of depression in women. Provided is data on the amount of caffeinated coffee consumed and whether the woman was diagnosed with clinical depression. Of interest is to see if there is evidence of an association between caffeinated coffee intake and clinical depression in women. What are the hypotheses? Caffeinated coffee Depression <1 cup/wk >=1 cup/day 2-3 cups/day 4+ cups/day Total Yes 670 1278 564 95 2607 No 11545 22573 11726 2288 48132 Total 12215 23851 12290 2383 50739 A. H0: H0 is not true and there is no association between caffeine intake and depression in women B. There is no association between caffeine intake and depression in women and H0 is not true C. Research indicates that there may be a relationship between caffeinated coffee consumption and risk of depression in women D. H0: There is an association between caffeine intake and…

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