Confidence interval
A range that likely contains the true value, with a stated confidence level.
A confidence interval is a range of values, built from sample data, that is likely to contain the true population parameter (such as a mean) at a chosen confidence level — commonly 95%. A 95% confidence interval means that if you repeated the sampling many times, about 95% of the intervals computed would contain the true value. It is not a 95% probability that the true value lies in this particular interval; the width reflects sample size and variability.
Example: A survey might report 52% support with a 95% confidence interval of 49%–55%.