What is the relationship between confidence levels and sample size?

What is the relationship between confidence levels and sample size?

The confidence level indicates how certain you are that the population parameter lies within your confidence interval. A higher confidence level requires a larger sample size to maintain the same margin of error.

Can you explain why a larger sample size is needed for higher confidence levels?

Sure! A larger sample size reduces the margin of error and increases the precision of your estimate, which is essential for higher confidence levels.

What are common confidence levels used in research?

Common confidence levels are 90%, 95%, and 99%. The 95% confidence level is the most widely used in research.

How does sample size affect the margin of error?

As the sample size increases, the margin of error decreases. This means your estimates become more accurate.

Can you give an example of calculating sample size for a specific confidence level?

Absolutely! For a 95% confidence level, you can use the formula: n = (Z^2 * p * (1-p)) / E^2, where Z is the Z-score, p is the estimated proportion, and E is the margin of error.