Research questions?
When controlling for age and geographic location, people who has taken at 4 or more seminars on prevention obesity are more likely to be obese than a person who has taken less than 4 seminars on prevention of obesity.
1. What is the effect size that I will use for my sample?
2. What else do I need consider when computing the sample size from statistical point of view?
An easy way to do this is to get people who are the same weight, and then send them to the seminar while you don’t send others.
In the event that this is impossible, find peoples lost weight percentage compared to their previous weight, and that is how you will graph it.