Suppose we know two of the three people have Alzheimer's disease. What is the conditional probability that they are both younger than 80 years of age?

Answer: 0.1064

Step-by-step explanation:

D = Both Alzheimer's are less than 80years old.

E = Two of 3 people who have Alzheimer's.

P (D | E) = P (D ∩ E)

P (E)

= P (A ∩ B ∩ C)

P (A ∩ B ∩ C) + P (A ∩ B ∩ C) + P (A ∩ B ∩ C)

= Pa * Pb * (1 - Pc) Pa * Pb * (1 - Pc) + (1 - Pa) * Pb * Pc + Pa * (1 - Pb) * Pc

= 0.0017

=0.0010+0.0017+0.0037

=0.1064