Confidence Interval Calculator

Calculate confidence intervals for a population mean using sample mean, standard deviation, and sample size with 90%, 95%, 99%, or 99.9% confidence levels.

How to Use Confidence Interval Calculator

Enter your sample mean, standard deviation, and sample size, then select a confidence level. The calculator computes the confidence interval bounds, margin of error, and standard error using the z-score method.

Step-by-Step Instructions

  1. Enter the sample mean, standard deviation, and sample size
  2. Select the desired confidence level (90%, 95%, 99%, or 99.9%)
  3. Click Calculate to compute the confidence interval
  4. View the interval bounds, margin of error, and formula

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