You want to determine if diet impacts body weight You recruit 60 subjects assigning 20 each to either one of two dietary interventions or to maintain their normal diet You measure body weight before and after the intervention and calculate the change in body weight post minus pre weights Shapiro Wilk tests show the following Diet 1 p 0 032 Diet 2 p 0 001 Normal Diet p 0 025 To determine the diet effect on the calculated change in body weight you would use a Assume all other assumptions are met for a parametric test O Friedman s test One way repeated measures ANOVA