so far I couldn´t find a solution to calculate the required sample size for the following scenario:

Goal:

**Research continuous variables (cost perceptions) of a population through one sample group.**--> means of one group need to be significant for the entire population.

Population: 7.500.000

Confidence Level: 95%

Confidence Interval: 3

Are there any information missing like power level and does anyone know how I can calculate the required sample size for this scenario? Especially through an online tool would be highly appreciated.

Thanks very much.

Chris