This site gives a definition and an example of numerical summaries. Topics include mean, median, quantiles, variance, and standard deviation.
As quoted on the site, "This website ... offers the possibility to download true random numbers generated using a quantum random number generator upon demand. Users can specify the length of the random number sequence and their upper boundary."
This page generates a graph of the sampling distribution of r, the Pearson correlation coefficient. Upon opening, the applet prompts for sample size greater than 6. The applet also displays the probabilities associated with the distribution.