Question

According to a survey on us population, the probability that a man will live seventy-five years is 0.62 and that he will live up to eighty-five years is 0.023. if mr. clooney is seventy-five years old, what is the probability he will survive to eighty-five years? express the probability as a percentage. include in your final answer the calculations necessary to arrive at the probability.

Answer 1

The answer is 3.71%

Given: .62 probability of reaching 75 years old and 0.023 probability of reaching 85 years old
   Since Mr. Clooney already reached 75 years old, we'll divide the probability of reaching 85 by the probability of reaching 75.
   .023 / .62 = .0370967742 x 100 = 3.71%

Why? Assume there are 1000 men who were born at the same time.
0.62 * 1000 = 620 of them will make it to 75.
0.023 * 1000 = 23 of them will make it to 85.
The proportion of those who will make it to 85 assuming that they already made it to 75 will be 23 / 620 = 0.0370967742 (same as above)