you are testing a new medication for relief of migraine headache pain, you randomly assign 26 of the subjects to the new medication and 25 of the subjects to the traditional medication the amount of time to achieve headache relief is then compared between these two groups what type of study is this?
1 an observational study based on a multistage sample
2 a matched pairs experiment
3 a randomized experiment
4-observational study based on stratified random sample
5- an observational study based on simple random sample
6- a randomized bolck experiment