This section of the Engineering Statistics Handbook gives the normal probability density function as well as the standard normal distribution equations. Example graphs of the distributions are shown and a justification of the Central Limit Theorem is included.
This simulation applet shows groups of confidence intervals for a given alpha based on a standard normal distribution. It shows how changes in alpha affect the proportion of confidence intervals that contain the mean. An article and an alternative source for this applet can be found at http://www.amstat.org/publications/jse/v6n3/applets/confidenceinterval.html.
This website is a collection of analysis tools commonly used in statistics and mathematics. These tools are divided into 7 categories: 1) Summarizing Data 2)Computational Probability 3)Requirements for most tests and computations 4) One population and one variable 5)One population and two or more variables 6)Two or three populations and one variable 7) Several populations and one or more variables