95% Confidence Interval: Mean 500, SD 50, n = 50
A sample of 50 with mean 500 and SD 50 produces a 95% confidence interval of approximately 486.14 to 513.86.
How to use this tool
- Enter sample mean (x̄), sample standard deviation (s), sample size (n) and z* (confidence level) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your lower bound and the full breakdown beneath it.
Use this preset to find the 95% confidence interval for a moderate-sized sample with mean 500 and standard deviation 50.
Frequently asked questions
- How do I choose the z* value?
- Common critical z-values: 1.645 for 90% confidence, 1.960 for 95%, 2.576 for 99%. These assume a large enough sample (n ≥ 30) so the Central Limit Theorem applies.