Power on X 

Statistical power calculator
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WINKS, Windows KWIKSTAT 

WINKS makes statistical data analysis understandable and easy to perform for the researcher, student, or scientist. Award-winning statistics program with thousands of users in over 65 countries.
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statistiXL 

statistiXL is a powerful data analysis add-in for MS Excel. Its abilities include: ANOVA, Contingency Tables, Clustering, Correlation, Discriminant and Factor Analysis, GOF, Regression, Nonparametrics, PCA, Uni and Multivariate t-Tests and many more.
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