Variance Ratio Confidence Interval Calculator

Understanding Variance Ratio Confidence Interval

The confidence interval for the ratio of two population variances is used to estimate the range within which the true ratio of the variances of two populations lies. It's particularly useful in hypothesis testing to compare the variability of two groups.

To calculate this interval, we use sample variances and sample sizes from both populations. The F-distribution is employed because it is the distribution of the ratio of two chi-squared variables, which are related to sample variances.

A higher confidence level (e.g., 99%) results in a wider interval, providing more certainty that the true ratio falls within the calculated range. Conversely, a lower confidence level (e.g., 90%) yields a narrower interval with less certainty. This tool helps in statistical analysis where comparing variances is crucial.