The Fine Lines between Parameters and Statistics

When looking at data

parameters are consider to be measures of the whole population that are fixed, but cannot really be known

statistics are considered to be measures of samples from the population that can be known but can vary and are always inaccurate. The amount of inaccuracy is measured, but even these measures are inaccurate, so probabilities of being correct are often stated, along with possible margins of error

For example, if we stop and randomly ask 100 people their age we might find the average to be 40 years old. This is a statistic because it describes a sample.

However, if we look at the census data for the U.S. we find that the average age is in fact 38. This is a parameter because it theoretically describes the whole population.