Tõenäosusvahemik

Tõenäosusvahemik, also known as a confidence interval in English, is a statistical concept used to estimate the range of values within which a population parameter is likely to lie, based on a sample from that population. It is not a single value but rather a range, accompanied by a level of confidence. This confidence level, typically expressed as a percentage (e.g., 95% or 99%), indicates the probability that the interval contains the true population parameter if the sampling process were repeated many times.

For example, a 95% confidence interval for the average height of adult males might be calculated as 170 cm to 180 cm. This means that if we were to take many samples of adult males and calculate a confidence interval for each, approximately 95% of those intervals would contain the true average height of all adult males in the population. It is crucial to understand that a confidence interval does not state the probability that the true parameter falls within a specific calculated interval. Instead, it reflects the reliability of the method used to generate the interval.

The width of a confidence interval is influenced by several factors, including the sample size, the variability of the data, and the chosen confidence level. A larger sample size generally leads to a narrower interval, indicating a more precise estimate. Similarly, lower data variability results in a narrower interval. A higher confidence level, however, requires a wider interval to encompass the true parameter with greater certainty. Tõenäosusvahemik is a fundamental tool in statistical inference, helping researchers quantify the uncertainty associated with sample-based estimates.