Ivo Dinov
UCLA School of Medicine
These educational materials demonstrate the shapes and parameters for several commonly used discrete and continuous probability distributions. The interactive applets allow computation of tail probabilities and critical values for over 45 different families of distributions:
http://www.socr.ucla.edu/htmls/SOCR_Distributions.html
http://wiki.stat.ucla.edu/socr/index.php/SOCR_EduMaterials_DistributionsActivities