How do I choose the right sample size for my study?

How do I choose the right sample size for my study?

Choosing the right sample size depends on several factors, including the population size, the margin of error, and the confidence level you desire. What type of study are you conducting?

I'm conducting a survey for a new product launch.

For a product launch survey, consider your target market size and how precise you want your results to be. A common formula is n = (Z^2 * p * (1-p)) / E^2, where n is the sample size, Z is the Z-value, p is the estimated proportion, and E is the margin of error.

What if I don't know the estimated proportion?

If you don't have an estimated proportion, you can use 0.5, which maximizes the sample size. This is a conservative approach that ensures your sample is large enough to provide reliable results.

How can I determine the Z-value for my study?

The Z-value corresponds to your desired confidence level. For example, a 95% confidence level has a Z-value of 1.96. You can find Z-values in statistical tables or online calculators.