Visualizing a simple random sample: Simple Random Sample of Lotto Balls This applet animates the random sampling of lotto balls. The population size can be set anywhere between 1 and 144. Users can ...

A simple approximation is provided to the formula for the sample sizes needed to detect a difference between two binomial probabilities with specified significance level and power. The formula for ...

The stratified random sample is always at least as accurate on the average as the random sample and its relative efficiency is a monotone increasing function of the size of the sample. No general ...