Question

The Bayesian statistician Bruno de Finetti (1906–1985) began his 1973 book on probability theory with the declaration: "PROBABILITY DOES NOT EXIST." The capitals appeared in the original, so I imagine de Finetti wanted us to shout this statement. What he meant is that probability is a device for describing uncertainty from the perspective of an observer with limited knowledge; it has no objective reality. Discuss the globe tossing example from the chapter, in light of this statement. What does it mean to say "the probability of water is 0.7"?

Answer 1

It means that if we select a random point around the globe, there is a 70% = 0.7 probability that it represents water.

Explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

In this question:

We know, that the planet Earth is formed 70% by water, and the globe represents this. This means, as the statement says, the if we select a random point around the globe, there is a 70% = 0.7 probability that it represents water.