Please provide some insight about this experiment I'm doing concerning goldfish growth. Basically, I've gathered all my data, and now I'm trying to figure out a way to analyze it. The experiment was basically trying to see if water volume has a direct effect on goldfish growth. I used different volumes and allowed the fish to stay in these volumes for 51 days (following a strict protocol of feeding, cleaning, maintaining ect.). During that time comparative photos were taking of the different volume groups and surprising what me and my mentor noticed that all the groups pretty much stayed the same size. The smallest fish in the large volume was the same size as the smallest fish in the small volume; and the same thing with the largest fish. At the end of the 51 days I measured all the fish in the groups, which was their length in centimeters. My aim is to show that all the volume groups really showed no variation between one another. Currently, I'm using EXCEL and trying to show this using a Bell shaped Curve. However, is this the right approach?
I have attached my working numbers.
Measurements are in the A column (A2:A40). You will see that I do have a graph, but I'm uncertain if it can even be call a Bell shaped curve. Is there any other statistical approaches I could use? Please help me!!!!
Basically I want to know what can I do with these numbers.
4.6 Group 1
6.2 Group 2
6.1 Group 3
7.6 Group 4
8.3 Group 5
You have 5 treatments (different water volumes)
The Null hypothesis is that water volume has no direct effect on goldfish growth
The alternative ( research hypothesis ) is ...
The solution tests the hypothesis that the mean size of goldfish is the same across all treatments (different levels of volume of water).