ABSTRACT
Most people think that probability is the long-term relative frequency of an outcome in a repeatable random experiment. This definition is easy to understand, but it is not applicable to decision problems involving unique events, as we discussed in Chapter 2. For example, scientists cannot estimate the probability that the earth’s climate changes because of carbon emissions and deforestation by observing as they would, the outcomes of a repeatable experiment. Similarly, one cannot estimate the probabilities that the following propositions are true from repeated observations:
1. The shortest route from Portland, Oregon to Los Angeles is less than 2,000 miles. 2. By 2020, humans will land in Mars. 3. An engineer predicted the stress at a given hot point in a joint of an offshore
platform by using a commercial finite element code. The true value of the stress exceeds by 10% the calculated value.
