# Statistics & Probability Tools

> Averages, regression, probability distributions, hypothesis tests, Bayes, normal tables, box plots, sample size and random simulation.

- URL: https://qilingtools.com/en/tags/statistics
- Price: Free, no sign-up
- Privacy: Runs locally in the browser; files are never uploaded

## Tools (16)

- [Statistics Calculator](https://qilingtools.com/en/math/statistics): Free online statistics calculator: paste a data set for the mean, median, mode, range, quartiles, variance, standard deviation, standard error and outliers.
- [Combinations](https://qilingtools.com/en/math/combination): Free online combination and permutation calculator: exact C(n,r), P(n,r) and n! with big integers, plus repetition variants and the total number of subsets.
- [Random Numbers](https://qilingtools.com/en/math/random): Free online random number generator: integers or decimals in any range, with no-repeats and sorting, list shuffling and dice, from a cryptographic source.
- [Probability Distributions](https://qilingtools.com/en/math/probability): Free online probability calculator: z-scores and cumulative normal probabilities, P(X=k) and P(X≤k) for binomial and Poisson, plus the mean and variance.
- [Average Calculator](https://qilingtools.com/en/math/average): Free online average calculator: arithmetic mean, median, mode, geometric and harmonic mean and RMS in one pass, plus weighted averages for grades and GPAs.
- [Linear Regression](https://qilingtools.com/en/math/regression): Free online linear regression and curve fitting: paste x and y columns for the least-squares line, r, R², residuals, predictions and quadratic or cubic fits.
- [Chart Maker](https://qilingtools.com/en/chart): Free online chart maker: paste data from Excel or CSV to build bar, line, area, pie, donut and scatter charts, then download a 2× PNG or an editable SVG.
- [Probability Simulator](https://qilingtools.com/en/math/dice): Free online probability simulator: coin flips, d4-d20 dice, weighted spinners and urn draws over a million trials, with live histograms and a chi-square test.
- [Confidence Intervals & Tests](https://qilingtools.com/en/math/hypothesis-test): Free online statistical inference: confidence intervals for means and proportions, one- and two-sample tests with the statistic, df, p-value and decision.
- [Bayes’ Theorem](https://qilingtools.com/en/math/bayes): Free online Bayes calculator: enter a prior and likelihood (or prevalence, sensitivity, specificity) for the posterior, PPV, NPV and a natural frequency table.
- [Box Plot Maker](https://qilingtools.com/en/math/box-plot): Box and whisker plots from pasted columns: Tukey, TI-84, Excel INC/EXC or Minitab quartiles, 1.5×IQR and 3×IQR outliers, mean, notches, PNG/SVG export.
- [Standard Normal Table (Z Table)](https://qilingtools.com/en/math/normal-table): Interactive z table with left, right, mean-to-z and central areas, shaded charts and inverse lookup, plus t, chi-square and F critical value tables.
- [Sample Size & Power Calculator](https://qilingtools.com/en/math/sample-size): Sample size and power: survey proportions and means, two proportions, two-sample and paired t-tests (matches G*Power), A/B test size and duration.
- [Markov Chain Calculator](https://qilingtools.com/en/math/markov): Enter a transition matrix with exact fractions to get the state diagram, n-step matrix Pⁿ, stationary distribution, classification and absorbing-chain results.
- [Central Limit Theorem Simulator](https://qilingtools.com/en/math/clt): Probability simulations: an animated Galton board vs binomial and normal curves, the central limit theorem, law of large numbers and Monte Carlo π.
- [Chi-Square & ANOVA Calculator](https://qilingtools.com/en/math/anova): Chi-square goodness of fit and independence (Yates, Fisher exact, Cramér’s V), one-way and two-way ANOVA, Tukey HSD, Kruskal–Wallis and Levene’s test.