Statistics Toolbox is a quick and convenient tool for users to perform common tasks in statistics without writing computer programs. Statistics Toolbox currently provides three major statistics functions: 1. drawing and calculating pdf and cdf functions of common statistics distributions; 2. Performing common statistical tests; 3. Calculating sample size and statistical power. Statistics Toolbox uses the same algorithms as those used by R. For other versions of Statistics Toolbox please visit: http://www.biostat.jhsph.edu/~zji4/#Statisticstoolbox