Answer: Choice A) 0.25
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Explanation:
The notation P(A | T) is the same as saying P(A given T).
The "given T" means we know event T has happened. Therefore, the person we have selected has at least one tattoo. We focus only on the first column because of this.
We have m = 60 people ages 30-50 out of n = 240 people with tattoos.
This leads to the probability m/n = 60/240 = 1/4 = 0.25
There's a 25% chance we pick someone from the 30-50 age group if we know the person has at least one tattoo.
