Question

question1: 92% of Sardinians live more than 80 years, & 34% live fewer than 90 years. Determine the probability that a randomly chosen Sardinian lives more than 90 years, given that s/he lives more than 80 years.

a) .58 b) .63 c) .68 d) .72 e) .77

question2: Suppose P(β=1)=.4, P(β=2)=.6 & X~U(0,β). Determine P(X < .8).

a) .44 b) .48 c) .52 d) .56 e) .60

note: X ~ U(0, β)  P(X < t) = t / β for 0 ≤ t ≤ β

question3: Events A, B & C are pairwise independent. Which one of the following statements may not be true ?

a) P(AB') = P(A)[1 – P(B)]

b) P(B' | A) = P(B')

c) P(C | AB') =P(C)

d) P(B U C) = P(B) + P(C) – P(B)P(C)

e) p(CB) + P(CB') = P(C)

Answer 1