Statistics Tools

Mean Calculator opens this category because arithmetic mean is the statistic everyone reports and the one most likely to mislead when the data is skewed. A dataset of seven salaries where six earn $40,000 and one earns $400,000 has a mean of $91,429 — a number that describes nobody in the room. The tool shows mean, median, mode, range, variance, standard deviation, quartiles, IQR and skewness together so the gap between mean and median is immediately visible. A/B Test Significance Calculator sits alongside it here from the Marketing Calculators category: it runs a two-proportion z-test on split-test results and returns a real p-value, which is the same inferential statistics machinery that underlies hypothesis testing in every other field.