The following results are from an independent-measures, two-factor study with n=5 participants in each treatment condition. Use a two-factor ANOVA with α=.05 to evaluate the main effects and the interaction

Q1: Placebo effect of exercise In a high-profile research study, Crum and Langer (2007) performed an experiment to test whether the relationship between physical exercise and health is impacted by one's mindset: in other words, if there is any "placebo effect" of exercise. A sample of 84 randomly selected hotel workers in the United States were placed either into a treatment group (n=44) or control group (n=40) depending on which hotel they worked at. The treatment group was given information demonstrating how their work is good physical exercise, while the control group was not given this information. They measured the body mass index (BMI) for each worker before the experiment and again four weeks after the experiment. a. Are the treatment group and control group independent of each other, and if so why? b. Now consider the treatment group alone: are the measurements of BMI taken before and after the experiment independent of each other, and if so why? c. What is the most appropriate…

Trichotillomania is a psychiatric illness that causes its victims to have an irresistible compulsion to pull their own hair. Two drugs were compared as treatments for trichotillomania in a study involving 13 women. Each women took clomipramine during one time period and desipramine during another time period in a double-blind experiment. Scores on a trichotillomania-impairment scale, in which high scores indicate greater impairment, were measured on each women during time period. The average of the 13 measurements for clomipramine was 6.2; the average of the 13 measurements for desipramine as 4.2. (a) A paired t test was used to test whether the mean difference between these two drugs is 0, resulting in a test statistics t∗ = 2.47. Find the sample standard deviation Sd. (b) Find a 95% confidence interval for the mean difference between the two drugs and give the conclusion.

The data below are from an independent-measures experiment comparing three different treatment conditions. Use an ANOVA with a = .05 to determine whether these data indicate any significant differences among the treatments    Treatment 1 Treatment 2 Treatment 3   0 1 4 N = 12 0 4 3 G = 24 0 1 6 åX2 = 92 2 0 3           M = 0.5 T = 2 M = 1.5 T = 6 M = 4 T = 16   SS = 3 SS = 9 SS = 6