Usaldusinterval

Usaldusinterval, or confidence interval in English, is a statistical concept used to estimate the range within which a population parameter is likely to lie, based on sample data. It provides a measure of uncertainty associated with a sample estimate, such as a mean or proportion, by indicating the degree of precision and reliability of the estimate.

A confidence interval is typically expressed as a range with an associated confidence level, such as 95%. This means that if the same sampling process is repeated numerous times, approximately 95% of the calculated intervals would contain the true population parameter. The width of the interval depends on factors such as the variability in the data, the sample size, and the chosen confidence level; larger samples and lower variability tend to produce narrower intervals.

The calculation of a confidence interval involves selecting an appropriate statistical formula based on the data type and distribution. For example, for a mean with a known standard deviation, the interval is constructed using the standard error and the critical value from the normal distribution. For small samples or unknown standard deviations, the t-distribution is applied.

Confidence intervals are widely used in fields such as medicine, social sciences, and environmental studies to infer population characteristics from sample data and to assess the precision of statistical estimates. They help researchers and decision-makers understand the range of possible values and the associated uncertainty, facilitating informed conclusions and policy development.

In summary, the usaldusinterval is a fundamental tool in inferential statistics that summarizes the degree of confidence one can have regarding estimated parameters based on sample data.