Confidence intervals are useful when trying to estimate the true value of a population parameter based on a sample statistic. Confidence intervals provide a range of values within which the true population parameter is likely to fall, given a certain level of confidence.
For example, if a sample of 100 people is taken from a population and the mean age is calculated, a confidence interval can be calculated to determine the range of values within which the true mean age of the entire population is likely to fall.
Confidence intervals are useful in a variety of situations, including in statistical analysis, market research, and public opinion polling. They provide a way to quantify the uncertainty associated with an estimate and allow for the possibility of future samples producing different results.
Overall, confidence intervals are an important tool in statistical analysis that help researchers and analysts understand the reliability and precision of their estimates.