Answer:
The probability that a person is younger than 50 given that she uses onling banking is 1.5%
Step-by-step explanation:
The survey indicated that 50% of adults conducts their banking online.
P(online banking customers) =1/2
Of the total number of customer that bank online, the survey stated that 20% of them are younger than 50 years.
P(customers younger than 50 yrs) =1/5
Out of the 20% than are younger than 50, we were told that 15% of them conduct online banking.
P(younger than 50 online banking customer) =3/20
Therefore the the probability that a = person is younger than 50 given that she uses online banking is P = 3/20*1/5*1/2 =17==3/200 = 0.015 =1.5%
The probability that she is younger than 50 does not increase or decrease with additional information, it only makes it clearer.