The frequentist paradigm defines probability by repeatedly observing a phenomenon and measuring how often an event occurs. For a specified population, divide favorable outcomes by total outcomes. section 5.1 section 6.0
The counting interpretation supports several probability constructions:
- For a discrete event, count members satisfying the criterion and divide by the total population; the result cannot exceed 1. section 5.1
- For conditional probability, restrict the universe to the population satisfying the given condition, then count the target event within that restricted population. section 6.1.2
- For continuous variables, refine value buckets toward infinitesimal width; the limiting probabilities are represented by a probability density function. section 5.6
A population count
If Statsville has 100,000 adults and 25,000 are at least 6 feet tall, the frequentist probability of selecting an adult meeting that criterion is 25,000 / 100,000 = 0.25. For a conditional question, such as weight over 90 kg given height between 160 and 183 cm, use only the 48,000 people in that height range as the population. section 5.1 section 6.1.2
Equation 5.1
Use the equation view to inspect the favorable-outcomes-over-total-population formulation. section 5.1
