How to Measure Anything

• Douglas Hubbard

p.44 Rule of Five

There is a 93.75% chance that the median of a population is between the smallest and largest values in any random sample of five from that population.

p.46
The single sample majority rule

Given maximum uncertainty about a population proportion–such that you believe the proportion could be anything between 0% and 100% with all values being equally likely—there is a 75% chance that a single randomly selected sample is from the majority of the population.