Statistics question: is it possible to test sets of cumulative data for significant differences in rate?
I have three cumulative percentage graphs, measuring the germination rates of three different seed types. Is there a way to compare them and see if there are any statistically significant differences?
The seed types were planted in triplicate, on three dishes each (nine overall). Every day for the past few weeks I've observed how many seeds on each dish have begun germinating -- so for an individual dish I would have " Day 1: 0 ... Day 7: 14 ... Day 14: 29" etc, with each day's score a cumulative total. (There are 100 seeds on each dish, so it works as a percentage rate as well)
In Excel, I've graphed the average germination rates of the replicates, for a graph that resembles this one
. (with three lines plotted, and x-axis = time in days, y-axis = percent germinated).
So is there a way to compare these different rates statistically? I can use Excel, Minitab, SPSS, and R.