Question

The probability that an individual without college education earns more than $30000 is 0.2, where as the probability that a person with B.S. or higher degree earns $30000 is 0.6. the probability that a person chosen at random has B.S. degree is 0.3. what is the probability that a person has atleast a B.S. degree if it is known that he/she earns more than $30000?.

Answer 1

Formula:

Baye's formula for trees:

P(E/F)= P(E and F)/ P(F)

Hence to find the probability that a person has atleast a B.S. degree if it is known that he/she earns more than $30000=

P(at least BS degree or higher and earn more than $30000)/P(more than $30000)

From the tree diagram ,

= (0.3)*(0.6)/(0.6+0.2)

=0.18/0.8

=0.225