A national survey indicated that 50 % of adults conduct their banking online. It also found that 20 % are younger than 50, and that 15 % are younger than 50 and conduct their banking online. What is the probability that a person is younger than 50 given that she uses online banking? Has the probability that she is younger than 50 increased or decreased with the additional information?

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.