This calculator creates a confidence interval for a population mean using the following formula:

Confidence Interval = x +/- z*(s/√n)

where:

**x:**sample mean**z:**z-value that corresponds to confidence level**s:**sample standard deviation**n:**sample size

To create a confidence interval for a population mean, simply fill in the values below and then click the “Calculate” button:

90% Confidence Interval: **(5.896, 28.104)**

95% Confidence Interval: **(3.770, 30.230)**

99% Confidence Interval: **(-0.388, 34.388)**