How does this work though? I remember reading that Gallup does around 1,000 participants for its polls as that is all that you need to get meaningful data without a crazy margin of error. I figured that 2k-6K would be an adequate sample size for countries larger than here but I also remember that there was point of diminishing return on adding to the sample size. This is all based off me remembering stuff from my college stats class a long time ago so tell me how I am messing this up.
In order to calculate margin of error, you need a confidence level. So the survey didn’t specify which confidence level they were using which makes a world of difference in the margin of error. Confidence levels are 80%, 85%, 90%, 95% (most commonly used), and 99%.
Margin Of Error Calculator - SmartSurvey
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All you need is the population of the country, the estimated sample you think the surgery used and play around with different confidence levels.
Example
US population: 300 million
Sample from Survey: 48k
Confidence level: 95%
Margin of error: 0.45%
China population: 1.3 billion
Sample from survey: 6600 (although it’s not specified from the survey, I just assumed the highest)
Confidence level: 95%
Margin of error: 1.21%