HW 4

HW 4 Note: All of your statistical tests must be done so that you reject the null hypothesis at the alpha=. 05 or less. You must provide your raw data. 1. You are working for a pharmaceutical company and have been asked to determine if any of the three new antidepressants are effective in reducing the magnitude of depressive symptoms. You are also concerned if any of the new antidepressants are more efficacious (more effective) than the others. Patients were randomly assigned to one of four conditions. Neither the experimenter nor the patient knew what type of compound they were given. Group 1 was given a placebo, Group 2 was given the drug paroxetine, Group 3 was given the drug, fluvoximine, and Group 4 was given the drug fluoxetine. Patients were given the drug for two months and then given an assessment of overall depression. This is a 50­point scale, where low numbers indicate less depression and higher number indicate more depression. YOU NEED TO CREATE YOUR OWN DATA SET. PLEASE BE SURE TO GIVE ME YOUR DATA AS WELL AS ALL CALCULATIONS (30 Points) ? Be sure to answer the following: o Reframe the question into a research hypothesis (Alternative) and null hypothesis. Be sure to do this in words as well as symbolically o What does your statistical tests tell you about the research hypothesis. You must describe your results. o What is your eta squared from you statistical analysis. Describe what this number tell you about your experiment. o Based on your results what recommendations will you be able to make about these new antidepressants to the Vice President of Research and Development for this company 2. The University of the Arts has just hired you to determine if productivity of their faculty is related to job satisfaction. You decide to give a sample of faculty the Myerson job satisfaction questionnaire. This is a 25­question test and the higher the score the more satisfied the person is with their job. You also measure productivity based on the number of times the person has shown their art in a year in galleries. Create the data set and then decide what you can tell the Director of personnel. (20 points) 3. Discuss the differences between within group variance and between group variance. What does a t or F test test? (15 points) 4. I want you to design a study in which you want to predict the number of times that someone visits a health professional in a year. Note that you must make three predictions. You also need to tell me about the strength of the relationship between x and y. Be sure to tell what r squared is from your data and what this tells you about your data. In this problem you think that the number of mental health symptoms experienced in the same time period may be an important as a predictor variable. Make up the data set and carryout the appropriate quantitative test. Describe your findings and tell me how good are your predictions? (20 Points) 5. Discuss the concept of the standard error of the estimate (10 points) 6. If alpha = .085 can we reject the null hypothesis. Justify your answer. (5 points)