Respuesta :
Answer:
0.9976 = 99.76% probability that he/she actually is a future terrorist
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
P(B|A) is the probability of event B happening, given that A happened.
[tex]P(A \cap B)[/tex] is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Person identified as a future terrorist
Event B: Person is actually a future terrorist.
Probability that a person is identified as a future terrorist:
96% of [tex]\frac{1000}{200000000}[/tex]
100 - 99.8 = 0.2% of [tex]\frac{200000000-1000}{200000000}[/tex]
So
[tex]P(A) = 0.96\frac{1000}{200000000} + 0.002\frac{200000000-1000}{200000000} = 0.002[/tex]
Probability of being identified and being a future terrorist:
100 - 99.8 = 0.2% of [tex]\frac{200000000-1000}{200000000}[/tex]
[tex]P(A \cap B) = 0.002\frac{200000000-1000}{200000000} = 0.00199999[/tex]
What is the probability that he/she actually is a future terrorist
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.00199999}{0.00200479} = 0.9976[/tex]
0.9976 = 99.76% probability that he/she actually is a future terrorist
