Calculators

Calculates the degrees of freedom (df) for various statistical tests, representing the number of independent pieces of information available to estimate a parameter.

Calculates the median of a set of numbers. The median is the middle value in a dataset when the numbers are arranged in order.

Calculates probabilities related to the time until an event occurs in a Poisson process. The exponential distribution models the time until an event happens, given an average rate of occurrence.

Calculates the t-statistic, used in hypothesis testing when the population standard deviation is unknown. This calculator helps determine if the difference between a sample mean and a population mean is statistically significant.

Performs a Z-test to compare a sample mean to a known population mean or to compare two sample means when population variances are known.

Calculates the average of the absolute differences between each data point and the mean.

Performs a non-parametric test to compare differences between two independent groups when the assumption of normality is violated. It calculates the U statistic and associated p-value.

Calculates the entropy (average level of information, surprise, or uncertainty) inherent in a variable's possible outcomes.

Calculates the accuracy of a classification model, representing the proportion of correct predictions.

Calculates the pooled standard deviation, an estimate of the standard deviation for two samples assuming equal variance, often used in two-sample t-tests.