An experimental study because it will give the most accurate results.
Step-by-step explanation:
The observational study could also be somewhat useful, but the most accurate results will come from an experimental study. You will test the difference in DNA, blood pressure, and such. Whilst, the observational study, you only can observe the effects from the outside. The sample studies mean nothing because you can't test both sides of the complete study.
The fraction 5/10 is the same as 50/100 because they are equivalent. It will take 10 group of 10 to get to the denominator 100, so it will take 10 groups of 5 in the numerator to make it equal.
