# Which statistical test to use and why?

My project involves 1) Comparison of new samples against a control and 2) Find any effect on the speed of growth and germination % of seeds by treating them with the new samples

My question is, what kind of statistical analysis to carry out and an explanation on why to use that specific test.

I have a material called ICR which is set as a control. This materials is supposed to work excellent on seed growth on its own but it still needs some improvements. So by mixing some of the ICR with other materials, I came up with 4 different formulations (KCR, ACR, XKCR, XLCR) and tested them to compare whether they have improved or performed better than the ICR.

Test 1: Samples are all made in quintuplets. They all have the same concentration and amount of ICR and additives. The only variation is the type of additives. I obtained sample data, calculated the mean and the standard deviation of all four samples and the control. Now I need to compare my samples against the control and confirm that it has improved. How do I do that? I also want to compare among the samples and say whether they are the same or one of them outperforms from the rest.

Test 2A: Samples are all made in quintuplets. They all have 20 seeds. I have two controls this time. Control 1 has 6 ml of distilled water only. Control 2 has 6 ml of ICR. I have obtained the germination percentages. I want to use statistics to tell me which sample had the highest germination % and to confirm whether there was a significant difference between the controls and the samples, and among the samples due to the effect of treatments.

Test 2B: Same batch used from test 2A. This time I got 30 random seedlings from each batch and recorded the shoot and root length. I want to know whether the treatments had a significant effect on the growth of seeds compared to the control, or among the treatments. This time, I want to combine both the root and shoot measurements.