Answered: A researcher conducts an experiment…

A researcher conducts an experiment comparing two treatment conditions and wants to have 30 scores in each treatment condition. Which design would require the smallest number of participants?

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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During the 2004 senatorial campaign in a large southwestern state, illegal immigration was a major issue. One of the candidates argued that illegal immigrants made use of educational and social services without having to pay property taxes. The other candidate pointed out that the cost of new homes in their state was 20–30% less than the national average due to the low wages received by the large number of illegal immigrants working on new home construction. A random sample of 5,500 registered voters was asked the question, “Are illegal immigrants generally a benefit or a liability to the state’s economy?” The results were as follows: 3,500 people responded “liability,” 1,500 people responded “benefit,” and 500 people responded “uncertain.” a. What is the population of interest? b. What is the population from which the sample was selected? c. Does the sample adequately represent the population? d. If a second random sample of 5,000 registered voters was selected, would the results be…
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A clinical psychologist wants to test the effectiveness of three new therapies that have been developed for reducing anxiety symptoms. The researcher recruits 15 participants and randomly assigns them to take part in Therapy A, Therapy B, or Therapy C for a month. At the end of the month, the researcher measures the participants' anxiety symptoms on a scale from 1 to 10 (where a higher score means more anxiety symptoms). The participants' scores are shown below: What is the appropriate test to use ? 3. What are the null and alternative hypotheses ? 4. Using a two-tailed alpha of .05, determine what the critical value is 5. Calculate the test statistic 6. State whether you reject or fail to reject the null hypothesis for the omnibus test 7. Calculate and report the effect size for the omnibus test 8. Perform a Post-Hoc Test. Report the significance of each pairwise comparison
In a survey of working parents (both parents working), one of the questions asked was "Have you refused a job, promotion, or transfer because it would mean less time with your family?" Two hundred men and 200 women were asked this question. Twenty-nine percent of the men and 24% of the women responded "yes." a. Based on this survey, can we conclude that there is a difference in the proportion of man and women responding “yes" at the 0.05 level of significance? (i) State the null and alternative hypotheses (ii) What test statistics would you use and why? (iii) Compute the value of the test-statistic. (iv) What rejection region would you use? (v) State your conclusion in the context of the problem. b. What P-value is associated with this test? Based on this P-value, could H. be rejected at significance level 0.08? c. Find a 95% confidence interval for the difference between the proportion of men and women responding "yes." Based on this confidence interval, would your conclusion be the…
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Dr. Jarry applies for a research grant to examine whether electrolyte-enriched water affects athletic performance. They propose enrolling 50 college distance runners who will consume 28 ounces of water or 28 ounces of an electrolyte-enriched solution 30 minutes before running a timed 5000 meter race. Dr. Jarry states that runners will be randomly assigned to the control group (distilled water) or the treatment group (electrolyte- enriched water). Both the electrolyte solution and the distilled water will be provided to the runners in unlabeled opaque bottles. The electrolyte solution is identical in appearance and taste to distilled water. Unfortunately, the funding agency rejects the proposal due to inadequate blinding procedures. Which of the following might have been a reason for the funding agency to reject the proposal? It is not clear whether the researcher is blinded It is not clear whether the subjects are blinded It is not clear whether either the researcher or the subjects…
Treatment for Cocaine AddictionCocaine addiction is very hard to break. Even among addicts trying hard to break the addiction, relapse is common. (A relapse is when a person trying to break out of the addiction fails and uses cocaine again.) A study is conducted to investigate the effectiveness of two drugs, desipramine and lithium, in the treatment of cocaine addiction. The subjects in the six-week study were cocaine addicts seeking treatment. The 72 subjects were randomly assigned to one of three groups (desipramine, lithium, or a placebo, with 24 subjects in each group) and the study was double-blind. Now we are able to consider all three groups together and test whether relapse rate differs by drug. Ten of the subjects taking desipramine relapsed, 18 of those taking lithium relapsed, and 20 of those taking the placebo relapsed. (a) Create a two-way table from the information given. Relapse No relapse Total Desipramine ? ? ? Lithium ? ? ? Placebo ? ? ? Total ? ? ?…
Two different blood pressure medicines are being compared to determine if the average reduction in blood pressure is the same for each medication. The goal of the study is to determine if the medications differ. Twenty men age 50-60 years old are selected for the study. Ten men are chosen at random to receive the first medication and the other 10 men receive the second medication. Each of the 20 men is monitored for one month to determine the change in blood pressure over that time. Minitab provides the 95% confidence interval for (mu1 - mu2) (2.63, 14.18) a. Interpret this 95% CI. b. What assumptions (be specific) are necessary to construct this CI?
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A. Headache Pain : There are many over-the-counter pain relievers. By the end of the semester, you have a tremendous headache and are looking for the most effective pain relief available. You conduct a study comparing the three most popular pain relievers and a placebo to see which work best. You use only subjects with headaches and record the amount of time (in minutes) it takes for their headache to go away after they receive the medication. You randomly assign 60 participants to one of the four conditions using a double- + blind procedure. (Use a = Placebo 70 Drug A 30 Drug B 10 Drug C 10 30 60 40 20 50 40 10 10 60 30 40 10 10 40 30 30 30 30 30 10 40 20 20 20 60 40 20 30 50 30 30 10 30 30 20 20 60 20 10 10 20 40 20 30 20 50 20 10 40 20 30 30 State the hypotheses Critical value and df Test statistic