I'm really bad at stats and am running an experiment looking at growth rate or individuals over the period of 28 days. I collected data on Day 0, 7, 14, 21, and 28 so I have 5 data points. I would like to compare the two to the control group to see if they are statistically different and then compare the two different treatment groups to see if those are statistically different. To clarify, I would really like to look at the rate of growth. What is the best way to organize my data (do I need to subtract subsequent weeks?) and which type of stats tests should I run (one-way ANOVA or two-way i literally have no clue)? Any specifics would be great.
PS-I have access to and some familiarity with JMP and I have StatPlus for XCEL