Use SPSS or R to answer the following problems.Include screenshots of your SPSS or R output in your answers. Submit the homework as a word document with both the output and your responses to each question. Total: 50 points
1. I’m interested in the effect ofpet ownership on stress levels. I gather a sample of 90 UTEP students and measure their level of self-reported stress (scale of 1-10, where 1 is very little stress and 10 is extremely high amount of stress) at the beginning, middle, and end of the semester. 30 students have a pet dog, 30 students have a pet cat, and 30 students have no pet. SPSS users should use the data in the “PetStress_wide.txt” file and R users should use the data in the “PetStress_long.txt” file on Blackboard. Run a mixed ANOVA to test this relationship.
a)What is the outcome variable? (2 points)
b)What are the two predictor variables? Is each predictor measured within-subjects or between-subjects? (4 points)
c)Do the data satisfy the assumption of sphericity? Report the results of Mauchly’s test in APA style (include dfs, chi-square test statistic, and p value). (4 points)
oDetermined by Mauchly’s test, it’s indicating the assumption of sphericity was violated,X2(2)= 17, p
oAccording to the Greenhouse-Geisser correction, it’s determined that the effect of time was significant,F(1.7, 147.1) = 98.64, p
d)Is there a significant main effect for each predictor? Write out the main effect of each predictor in APA style. If you use a correction, report which correction you are using. (8 points)
e)Is there a significant interaction? Write out the interaction in APA style. If you use a correction, report which correction you are using. (4 points)
f)What are the group means? (6 points)
g)Run post-hoc tests to distinguish how the students with different types of pets compare to each other at the end of the semester. How does each pet condition compare to the others and is the comparison significant? Include p-values for each comparison. (9 points)
h)Copy and paste all relevant output for Question 1 here: (8 points)
2. Create an example of a research question that you would use a mixed ANOVA to test. Describe the predictor and outcome variables, how you would measure them, and the experimental design. (5 points)