Confidence Interval Calculator
Determine the range for your estimates with our easy-to-use calculator.
For finite populations, providing population size improves accuracy.
Confidence Interval: (%, %)
This is the range within which the true population parameter is likely to fall.
Understanding Confidence Intervals
A confidence interval is a range of values that's likely to include a population parameter with a certain degree of confidence. It helps in understanding the uncertainty associated with estimating population parameters from sample data. For example, a 95% confidence interval means that if we were to take many samples and compute a confidence interval for each sample, about 95% of these intervals would contain the true population parameter.
The confidence level (like 95%) indicates the probability that the confidence interval contains the true population parameter. Common confidence levels are 90%, 95%, and 99%. The choice of confidence level depends on the desired balance between precision and certainty.
This calculator uses the formula for confidence intervals for proportions, assuming a simple random sample. For finite populations, it applies a correction factor to improve accuracy. Remember that confidence intervals are based on statistical assumptions, and their validity depends on these assumptions being met.