Free Student
System of Equations Solver | 2×2 & 3×3 Linear Systems with Steps
Solve 2×2 and 3×3 simultaneous linear equations using Cramer’s Rule determinants, elimination, and matrix methods.
Statistical Power Calculator – 1-beta, Effect Size & Sample Size
Compute statistical power (1 – beta), Type II error risk, Cohen’s d effect size, and determine sample size for two-sample tests.
Statistical Power & A/B Test Sample Size Calculator
Calculate required sample sizes and test duration for A/B testing and hypothesis testing. Evaluate statistical power (1 – beta), significance alpha, and MDE uplift.
Standard Error Calculator – SEM, Proportion & FPC Correction
Calculate Standard Error of the Mean (SEM), finite population correction (FPC), standard error of proportion, and confidence bounds.
Standard Deviation Calculator – Free Sample (s) & Population (σ) Estimator
Calculate sample and population standard deviation, variance, and SEM.
Spearman Rank Correlation Calculator – rho (rs) & p-Value
Compute Spearman rank correlation coefficient rho (rs), rank assignment table with tie corrections, monotonic strength, and t-test.
Skewness Calculator – Sample & Population Asymmetry Analysis
Analyze third standardized moment asymmetry, Fisher-Pearson G1, and tail direction.
Normality Test Calculator – Jarque-Bera, Skewness & Kurtosis
Evaluate dataset normality using sample skewness, excess kurtosis, and the Jarque-Bera omnibus test with exact Chi-Square p-values.
Sample Size Calculator – Free Survey & Research Cohort Sizing Tool
Determine required survey sample sizes with finite population correction.