Usaldusastme

Usaldusastme, often translated as confidence interval, is a statistical concept used to estimate a population parameter. It provides a range of values, within which the true population parameter is likely to lie, with a certain level of confidence. This confidence level, typically expressed as a percentage (e.g., 95%), indicates the probability that if the same sampling procedure were repeated many times, the calculated confidence intervals would contain the true population parameter.

A confidence interval is constructed from sample data and is defined by two values: a lower limit and an upper limit. The width of the confidence interval is influenced by factors such as the sample size and the variability of the data. A larger sample size generally leads to a narrower interval, indicating a more precise estimate. Similarly, lower variability in the data also results in a narrower interval.

It is important to understand that a confidence interval does not state the probability that the true population parameter falls within a *specific* calculated interval. Instead, it refers to the long-run success rate of the method used to construct the interval. For example, a 95% confidence interval means that if we were to construct 100 such intervals from different samples of the same population, we would expect approximately 95 of them to contain the true population parameter.