A confidence interval is a range of values that is used to estimate an unknown population parameter based on a sample of data. It provides a measure of the precision and accuracy of an estimate, and gives an indication of the uncertainty surrounding it.
The interval is calculated from the sample data, and is expressed as a range of values that is believed to contain the true population parameter with a specified level of confidence. The level of confidence is usually expressed as a percentage, and is determined by the size of the sample and the variability of the data.
Confidence intervals are commonly used in statistical analysis, and are an important tool for making decisions and drawing conclusions about population parameters based on sample data.