Hello,
I was given a scenario that does not state a power value nor a mean or population size. How can I use proc power to solve for this scenario and problem set?
A researcher would like to examine whether there is a relationship between recent influenza vaccination (this season: yes/no) and a history of having the flu in the past 3 years (yes/no). She would like to detect a minimum difference in proportions of .10, and she expects a proportion of 0.35 in the reference group. She wants to limit falsely rejecting the null to 1%, and falsely rejecting the alternative hypothesis to 90%. What is the minimum sample size per group, given these criteria?
1) To detect a minimum difference of 0.10 (i.e., between 0.35 and 0.45) the minimum sample size per group is _____
I pointed you to an example in your previous thread.
Then others also gave examples. And now you repeat the question.
If the question is about sample size then you must provide a power. Proc Power will only estimate 1 missing property.
If you do not know a power then you can request analysis at multiple likely values for power and either pick one or show the range: Power = .7 .8 .9 for example. You will get 3 scenarios. Similar for estimated "means" involved. Literature
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