State that the gold standard for a random sample is one where all individuals can be assigned a number in a finite population and a proportion of the numbers are randomly selected but explain that in ...

This web calculator conducts a z-test for the difference between two populations' proportions. The calculator includes an explanation of inputs and outputs. This web calculator conducts a z-test for ...

Demographics can include any statistical factors that influence population growth or decline, but several parameters are particularly important: population size, density, age structure ...

Pennsylvania is one of only a few states in the U.S. that has a shrinking overall population. However, a handful of counties in the Buckeye State have seen their population boom in recent years.

A two-sample z-test for population means compares two population means. It is appropriate when the population standard deviations are known and the sample sizes are large. This web calculator conducts ...