This page gives a description of correlation, Pearson's r, Spearman's rho. There are some scatterplots illustrating the different values of r.
The page calculates summary statistics for any dataset. Users will be prompted for sample size when opening this page. The calculator returns mean, sum of X, sum of X^2, variance, standard deviation, and standard error. Key word: Descriptive statistics.
This page will perform basic multiple regression analysis for the case where there are several independent predictor variables, X1, X2, etc., and one dependent or criterion variable, Y. Requires import of data from a spreadsheet.