A pharmaceutical company tested the impact of four cholesterol-reducing medications(denoted A, B, C and D) on people at high risk of heart attack. For this clinical trial20 volunteers with LDL (bad) cholesterol levels of 140 mg/dl were randomly assigned toone of the four medications. The subjects were instructed to take one tablet per dayfor a period of three months after which their LDL levels were again measured. Beloware the amounts (in mg/dl) by which the LDL levels decreased after the three month trial.Medication A Medication B Medication C Medication D2931303130.5303231.530.53231.75353129.7527332931.53329(d) What assumptions are needed to make this test valid?(e) If a key assumption in (d) is not satisfied, test if the data provide sufficient ev-idence to indicate that at least one of the medications produces a mean reduc-tion in LDL cholesterol that is different from any of the other medications usinga non-parametric method (show all working and include appropriate hypothesisstatements).(f) Test if there is any significant difference in the mean reduction in LDL cholesterolusing Medication A compared with Medication D (show all working and includeappropriate hypothesis statements).

The assumptions needed for the test in part (c) are:Observations in each of the four groups…

Answered: A pharmaceutical company tested the…

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 new drug for pain relief is being tested within a given palliative care population. The new drug is being compared to an already approved pain relief drug that is commonly used in providing palliative care to patients who experience chronic severe pain. Assume the patients are asked to rate the pain on a scale from 1 to 10, and the data presented below was obtained from a small study designed to compare the effectiveness of the two drugs. Set up and interpret the results of a Mann-Whitney U test with an alpha of .05. Pain Rating as Reported by Patients Old Drug 1 3 3 4 6 New Drug 1 2 3 3 7 A) We fail to reject H0, which states the two populations are equal at the alpha equals .05 level because the calculated Uvalue of 10.5 is greater than the critical U value of 2. B) We fail to reject H0, which states the two populations are equal at the alpha equals .05 level…
Have you ever been frustrated because you could not get a container of some sort to release the last bit of its contents? An article reported on an investigation of this issue for various consumer products. Suppose five 6.0 oz tubes of toothpaste of a particular brand are randomly selected and squeezed until no more toothpaste will come out. Then each tube is cut open and the amount remaining is weighed, resulting in the following data: 0.52, 0.63, 0.43, 0.5, 0.35. Does it appear that the true average amount left is less than 10% of the advertised net contents? USE SALT (a) Check the validity of any assumptions necessary for testing the appropriate hypotheses. O The sample was selected to represent a range of results and the normal probability plot is not acceptably nonlinear. O The sample was selected to represent a range of results and the normal probability plot is not acceptably linear. The sample was randomly selected and the normal probability plot is acceptably linear. O The…
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In a study conducted at Virginia Tech, the plasma ascorbic acid levels of pregnant women were compared for smokers versus nonsmokers. Thirty women in the last three months of pregnancy, free of major health disorders and ranging in age from 15 to 32 years, were selected for the study. Prior to the collection of 20 ml of blood, the participants were told to avoid breakfast, forgo their vitamin supplements, and avoid foods high in ascorbic acid content. From the blood samples, the accompanying plasma ascorbic acid values were determined, in milligrams per 100 milliliters. Is there sufficient evidence to conclude that there is a difference between plasma ascorbic acid levels of smokers and nonsmokers? Assume that the two sets of data came from normal populations with unequal variances. Use a P-value. Click the icon to view the plasma ascorbic acid values. Let sample 1 be the nonsmokers and let sample 2 be the smokers. State the null and alternative hypotheses. Hoi Hi-H2 = 0 (Type integers…
Recall that small effects may be statistically significant if the samples are large. A study of small-business failures looked at 153 food-and-drink businesses. Of these, 107 were headed by men and 46 were headed by women. During a three-year period, 17 of the men's businesses and 7 of the women's businesses failed. (a) Find the proportions of failures for businesses headed by men (sample 1) and businesses headed by women (sample 2). These sample proportions are quite close to each other. p̂men = p̂women = Give the P-value for the z test of the hypothesis that the same proportion of women's and men's businesses fail. (Use the two-sided alternative.) The test is very far from being significant. (Round your test statistic to two decimal places and your P-value to four decimal places.) z = P-value = (b) Now suppose that the same sample proportions came from a sample of 30 times as large. That is, 210 out of 1380 business headed by women and 510 out of 3210 businesses…
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Healthy men aged 21–35 were randomly assigned to one of two groups: half received 0.82 gram of alcohol per kilogram of body weight; half received a placebo. Participants were then given 30 minutes to read up to 34 pages of Tolstoy’s War and Peace (beginning at Chapter 1, with each page containing approximately 22 lines of text). Every two to four minutes, participants were prompted to indicate whether they were “zoning out.” The proportion of times participants indicated they were zoning out was recorded for each subject. The following table summarizes data on the proportion of episodes of zoning out. Group n S Alcohol 25 0.25 0.05 Placebo 25 0.12 0.03 Do we have evidence to claim that two groups have different means?
The background concentration of a chemical in soil was measured on ten random specimens of soil from an uncontaminated area. The measured concentrations, in mg/kg, are: 1.4, 0.6, 1.2, 1.6, 0.5, 0.7, 0.3, 0.8, 0.2, and 0.9. Soil from a neighboring area will be declared “contaminated” if test specimens contain a chemical concentration higher than the upper 99% confidence limit of the background level. What is the cleanup target concentration?
A researcher would like to examine how the chemical tryptophan, contained in foods such as turkey, can affect mental alertness. A sample of n = 9 college students is obtained and each student’s performance on a familiar video game is measured before and after eating a traditional Thanksgiving dinner including roast turkey. The average score dropped by M = 14 points after the meal with SS = 1152 for the difference scores. A. Is there is significant difference in performance before eating versus after eating? Use a two-tailed test with α = .05. SMD = ___________________________ tcritical = ________________________ tcalculated = ________________________ Decision = _______________________ B. Compute r2 to measure the size of the effect. r2 = _____________________________ C. Write a sentence demonstrating how the outcome of the test and the measure of effect size would…
A deficiency of the trace element selenium in the diet can negatively impact growth, immunity, muscle and neuromuscular function, and fertility. The introduction of selenium supplements to dairy cows is justified when pastures have low selenium levels. Authors of a research paper supplied the following data on milk selenium concentration (mg/L) for a sample of cows given a selenium supplement (the treatment group) and a control sample given no supplement, both initially and after a 9-day period. Initial Measurement Treatment Control 11.4 9.1 9.6 8.7 10.1 9.7 8.5 10.8 10.2 10.9 10.6 10.6 11.9 10.1 9.9 12.3 10.7 8.8 10.2 10.4 10.3 10.9 11.4 10.4 9.3 11.6 10.6 10.9 10.9 8.3 After 9 Days Treatment Control 138.3 9.2 104 8.9 96.4 8.9 89 10.1 88 9.6 103.8 8.6 147.3 10.4 97.1 12.4 172.6 9.2 146.3 9.5 99 8.4 122.3 8.8 103 12.5 117.8 9.1 121.5 93 (a) Use the given data for the treatment group to determine if…

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