Sample Size (Statistics)
Dear forum pal,
Here is my problem:
- We would like to buid an experiment in order to check the effect of a new energy drink that is destined to the olympic sprinters (100m).
- Here are our requirements for the experiment.
- Type I error = alpha = less than 0.05
- Power = 1-beta = better than 0.80
If the results difference over 100 meter between someone who used the drink and someone who did not is 0.1%, what is the required sampling size ?
Same question for a difference of 0.2 %, 2.5%, 3.6%, 4.0% and 4.7%
Please try to help us.
If our question lacks any other information please let us know.
You'll need at least three things you have not specified.
How to calculate Beta.
What have you?
Thank you TKHunny
Thank you very much for your quick reply.
Please receive the missing information.
The null hypothesis is that there is no difference between a sprinter that have consumed the drink and a sprinter that have consumed mineral water.
The Alternate hypothesis is that there is a difference between the 2 sprinters and that this difference improves the results in seconds (over 100m) of 0.1% (sprinter with energy drink better than sprinter with water). Other experiments would have alternate hypothesis of improving the results for 0.2%, 2.5%, 3.6%, 4.0% and 4.7%.
Concerning the beta, since beta=(1-statistical power of the experiment) and since such experiments in order to be valid should have a power of at least 0.80 then beta=0.2
I have found a nice site that makes automatic calculations I don't know how to use it properly (I am weak in statistics, my basic expertise is Food Formulation and Innovation). I wonder if we can post links on this forum but you can find the tool on dssresearch.com then click researcher's toolkit and then sample size calculator and then percentages. But you are the expert TKHunny, You surely know better than me how to find the answer...
Thank you again for your precious help, it is highly appreciated.