Question

Just looking for guidance on what test i need to run for this and why 3. A physical education teacher wants to know if there are differences in % body fat between the 4th grade classes of three different schools. She measured three variables, time in the mile run (min), % body fat and sit-ups. a. What type of statistical test the researcher needs to run? Be specific in explaining why. b. Run the appropriate analysis, and determine and explain the results using the SPSS output.

Answer 1

We have the data for percentage of body fat for three different schools. Now, you want to test whether the mean body fat percentage for three different schools differs significantly or not. Classical one-way ANOVA with three groups fits here to answer the question. Also, one can employ non-parametric one-way ANOVA - which is the Kruskal-Wallis test of rank because usual parametric anova assumes the homoscedasticity of all observations irrespective of groups and normality. Which may not be valid here because the response is percentage here. So, I think to be safe you can conduct Kruskal-Wallis Test to test the difference.