There's a great question/answer at: Calculating probabilities over different time intervals
This is an awesome answer, but I'd like to ask a related question:
What if the period goes the other direction, for example, the probability is determined for a year, but you want to see the probability of it happening over 50 years?
For example, let's say there's a 5% chance of a fire during the course of a month. How likely would this be over the course of a year? What about over 30 years?
And, what if there's a 5% chance during 5 months of the year, and 10% chance during 7 months of the year. What would be the chance of a fire during the year? What about over 30 years?
Thanks in advance!